From fac69e52b7f0d38f06d28434322f3cb69460104d Mon Sep 17 00:00:00 2001
From: Boger <kotvberloge@gmail.com>
Date: Wed, 18 Mar 2020 17:04:11 +0300
Subject: [PATCH] :poop: First iteration

---
 aiogram/api/client/base.py                    |  21 +-
 aiogram/api/client/bot.py                     |   4 +-
 aiogram/api/client/session/aiohttp.py         |   8 +-
 aiogram/api/client/session/base.py            |  24 +-
 aiogram/api/methods/base.py                   |  21 +-
 aiogram/api/types/base.py                     |   2 +-
 aiogram/api/types/input_file.py               |  14 +-
 aiogram/api/types/message.py                  |   2 +-
 aiogram/api/types/user.py                     |   2 +-
 aiogram/dispatcher/dispatcher.py              |  12 +-
 aiogram/dispatcher/event/handler.py           |  28 +-
 aiogram/dispatcher/filters/__init__.py        |   8 +-
 aiogram/dispatcher/filters/base.py            |  30 +-
 aiogram/dispatcher/filters/command.py         |   2 +-
 aiogram/dispatcher/filters/text.py            |   2 +-
 aiogram/dispatcher/handler/base.py            |  20 +-
 aiogram/dispatcher/handler/message.py         |   8 +-
 aiogram/dispatcher/router.py                  |  12 +-
 aiogram/utils/helper.py                       |  70 +++--
 aiogram/utils/mixins.py                       |  91 +++---
 mypy.ini                                      |  19 +-
 poetry.lock                                   | 260 +++++++++++-------
 pyproject.toml                                |   2 +-
 .../test_session/test_base_session.py         |   3 +-
 tests/test_utils/test_mixins.py               |  35 +--
 25 files changed, 427 insertions(+), 273 deletions(-)

diff --git a/aiogram/api/client/base.py b/aiogram/api/client/base.py
index 4d8b7453..c4f7aff3 100644
--- a/aiogram/api/client/base.py
+++ b/aiogram/api/client/base.py
@@ -1,9 +1,17 @@
 from __future__ import annotations
 
 from contextlib import asynccontextmanager
-from typing import Any, Optional, TypeVar
+from typing import (
+    Any,
+    AsyncIterator,
+    Optional,
+    TypeVar,
+)
 
-from ...utils.mixins import ContextInstanceMixin, DataMixin
+from ...utils.mixins import (
+    ContextInstance,
+    ContextInstanceMixin,
+)
 from ...utils.token import extract_bot_id, validate_token
 from ..methods import TelegramMethod
 from .session.aiohttp import AiohttpSession
@@ -12,13 +20,13 @@ from .session.base import BaseSession
 T = TypeVar("T")
 
 
-class BaseBot(ContextInstanceMixin, DataMixin):
+class BaseBot(ContextInstanceMixin[ContextInstance]):
     """
     Base class for bots
     """
 
     def __init__(
-        self, token: str, session: BaseSession = None, parse_mode: Optional[str] = None
+        self, token: str, session: Optional[BaseSession] = None, parse_mode: Optional[str] = None
     ) -> None:
         validate_token(token)
 
@@ -54,14 +62,15 @@ class BaseBot(ContextInstanceMixin, DataMixin):
         await self.session.close()
 
     @asynccontextmanager
-    async def context(self, auto_close: bool = True):
+    async def context(self, auto_close: bool = True) -> AsyncIterator["BaseBot[ContextInstance]"]:
         """
         Generate bot context
 
         :param auto_close:
         :return:
         """
-        token = self.set_current(self)
+        # TODO: because set_current expects Bot, not BaseBot — this check fails
+        token = self.set_current(self)  # type: ignore
         try:
             yield self
         finally:
diff --git a/aiogram/api/client/bot.py b/aiogram/api/client/bot.py
index 23586fc2..51058f1d 100644
--- a/aiogram/api/client/bot.py
+++ b/aiogram/api/client/bot.py
@@ -101,12 +101,12 @@ from ..types import (
 from .base import BaseBot
 
 
-class Bot(BaseBot):
+class Bot(BaseBot["Bot"]):
     """
     Class where located all API methods
     """
 
-    @alru_cache()
+    @alru_cache()  # type: ignore
     async def me(self) -> User:
         return await self.get_me()
 
diff --git a/aiogram/api/client/session/aiohttp.py b/aiogram/api/client/session/aiohttp.py
index 06a1c99d..b123bcfc 100644
--- a/aiogram/api/client/session/aiohttp.py
+++ b/aiogram/api/client/session/aiohttp.py
@@ -15,8 +15,8 @@ class AiohttpSession(BaseSession):
     def __init__(
         self,
         api: TelegramAPIServer = PRODUCTION,
-        json_loads: Optional[Callable] = None,
-        json_dumps: Optional[Callable] = None,
+        json_loads: Optional[Callable[..., str]] = None,
+        json_dumps: Optional[Callable[..., str]] = None,
     ):
         super(AiohttpSession, self).__init__(api=api, json_loads=json_loads, json_dumps=json_dumps)
         self._session: Optional[ClientSession] = None
@@ -27,11 +27,11 @@ class AiohttpSession(BaseSession):
 
         return self._session
 
-    async def close(self):
+    async def close(self) -> None:
         if self._session is not None and not self._session.closed:
             await self._session.close()
 
-    def build_form_data(self, request: Request):
+    def build_form_data(self, request: Request) -> FormData:
         form = FormData(quote_fields=False)
         for key, value in request.data.items():
             if value is None:
diff --git a/aiogram/api/client/session/base.py b/aiogram/api/client/session/base.py
index f31dd451..b7eeabd3 100644
--- a/aiogram/api/client/session/base.py
+++ b/aiogram/api/client/session/base.py
@@ -3,7 +3,16 @@ from __future__ import annotations
 import abc
 import datetime
 import json
-from typing import Any, AsyncGenerator, Callable, Optional, TypeVar, Union
+from types import TracebackType
+from typing import (
+    Any,
+    AsyncGenerator,
+    Callable,
+    Optional,
+    Type,
+    TypeVar,
+    Union,
+)
 
 from aiogram.utils.exceptions import TelegramAPIError
 
@@ -17,8 +26,8 @@ class BaseSession(abc.ABC):
     def __init__(
         self,
         api: Optional[TelegramAPIServer] = None,
-        json_loads: Optional[Callable[[Any], Any]] = None,
-        json_dumps: Optional[Callable[[Any], Any]] = None,
+        json_loads: Optional[Callable[..., str]] = None,
+        json_dumps: Optional[Callable[..., str]] = None,
     ) -> None:
         if api is None:
             api = PRODUCTION
@@ -37,7 +46,7 @@ class BaseSession(abc.ABC):
         raise TelegramAPIError(response.description)
 
     @abc.abstractmethod
-    async def close(self):  # pragma: no cover
+    async def close(self) -> None:  # pragma: no cover
         pass
 
     @abc.abstractmethod
@@ -73,5 +82,10 @@ class BaseSession(abc.ABC):
     async def __aenter__(self) -> BaseSession:
         return self
 
-    async def __aexit__(self, exc_type, exc_val, exc_tb):
+    async def __aexit__(
+        self,
+        exc_type: Optional[Type[BaseException]],
+        exc_value: Optional[BaseException],
+        traceback: Optional[TracebackType],
+    ) -> None:
         await self.close()
diff --git a/aiogram/api/methods/base.py b/aiogram/api/methods/base.py
index c1077701..e7fa1f2c 100644
--- a/aiogram/api/methods/base.py
+++ b/aiogram/api/methods/base.py
@@ -2,7 +2,16 @@ from __future__ import annotations
 
 import abc
 import secrets
-from typing import TYPE_CHECKING, Any, Dict, Generic, Optional, Type, TypeVar, Union
+from typing import (
+    Generator,
+    TYPE_CHECKING,
+    Any,
+    Dict,
+    Generic,
+    Optional,
+    TypeVar,
+    Union,
+)
 
 from pydantic import BaseConfig, BaseModel, Extra
 from pydantic.generics import GenericModel
@@ -24,7 +33,7 @@ class Request(BaseModel):
     class Config(BaseConfig):
         arbitrary_types_allowed = True
 
-    def render_webhook_request(self):
+    def render_webhook_request(self) -> Dict[str, Any]:
         return {
             "method": self.method,
             **{key: value for key, value in self.data.items() if value is not None},
@@ -48,7 +57,7 @@ class TelegramMethod(abc.ABC, BaseModel, Generic[T]):
 
     @property
     @abc.abstractmethod
-    def __returning__(self) -> Type:  # pragma: no cover
+    def __returning__(self) -> type:  # pragma: no cover
         pass
 
     @abc.abstractmethod
@@ -62,14 +71,14 @@ class TelegramMethod(abc.ABC, BaseModel, Generic[T]):
     async def emit(self, bot: Bot) -> T:
         return await bot(self)
 
-    def __await__(self):
+    def __await__(self) -> Generator[Any, None, T]:
         from aiogram.api.client.bot import Bot
 
         bot = Bot.get_current(no_error=False)
         return self.emit(bot).__await__()
 
 
-def prepare_file(name: str, value: Any, data: Dict[str, Any], files: Dict[str, Any]):
+def prepare_file(name: str, value: Any, data: Dict[str, Any], files: Dict[str, Any]) -> None:
     if not value:
         return
     if name == "thumb":
@@ -101,7 +110,7 @@ def prepare_media_file(data: Dict[str, Any], files: Dict[str, InputFile]) -> Non
         and isinstance(data["media"]["media"], InputFile)
     ):
         tag = secrets.token_urlsafe(10)
-        files[tag] = data["media"].pop("media")  # type: ignore
+        files[tag] = data["media"].pop("media")
         data["media"]["media"] = f"attach://{tag}"
 
 
diff --git a/aiogram/api/types/base.py b/aiogram/api/types/base.py
index 057c4b3d..8c098202 100644
--- a/aiogram/api/types/base.py
+++ b/aiogram/api/types/base.py
@@ -5,7 +5,7 @@ from pydantic import BaseModel, Extra
 from aiogram.utils.mixins import ContextInstanceMixin
 
 
-class TelegramObject(ContextInstanceMixin, BaseModel):
+class TelegramObject(ContextInstanceMixin["TelegramObject"], BaseModel):
     class Config:
         use_enum_values = True
         orm_mode = True
diff --git a/aiogram/api/types/input_file.py b/aiogram/api/types/input_file.py
index d6ec7d81..27b452cb 100644
--- a/aiogram/api/types/input_file.py
+++ b/aiogram/api/types/input_file.py
@@ -4,7 +4,13 @@ import io
 import os
 from abc import ABC, abstractmethod
 from pathlib import Path
-from typing import AsyncGenerator, Optional, Union
+from typing import (
+    AsyncGenerator,
+    AsyncIterator,
+    Iterator,
+    Optional,
+    Union,
+)
 
 import aiofiles as aiofiles
 
@@ -24,14 +30,14 @@ class InputFile(ABC):
         self.chunk_size = chunk_size
 
     @classmethod
-    def __get_validators__(cls):
-        yield
+    def __get_validators__(cls) -> Iterator[None]:
+        yield None
 
     @abstractmethod
     async def read(self, chunk_size: int) -> AsyncGenerator[bytes, None]:  # pragma: no cover
         yield b""
 
-    async def __aiter__(self):
+    async def __aiter__(self) -> AsyncIterator[bytes]:
         async for chunk in self.read(self.chunk_size):
             yield chunk
 
diff --git a/aiogram/api/types/message.py b/aiogram/api/types/message.py
index e2eeb478..5af79d25 100644
--- a/aiogram/api/types/message.py
+++ b/aiogram/api/types/message.py
@@ -181,7 +181,7 @@ class Message(TelegramObject):
     buttons."""
 
     @property
-    def content_type(self):
+    def content_type(self) -> str:
         if self.text:
             return ContentType.TEXT
         if self.audio:
diff --git a/aiogram/api/types/user.py b/aiogram/api/types/user.py
index f46d3f2b..e3a9eee1 100644
--- a/aiogram/api/types/user.py
+++ b/aiogram/api/types/user.py
@@ -32,7 +32,7 @@ class User(TelegramObject):
     """True, if the bot supports inline queries. Returned only in getMe."""
 
     @property
-    def full_name(self):
+    def full_name(self) -> str:
         if self.last_name:
             return f"{self.first_name} {self.last_name}"
         return self.first_name
diff --git a/aiogram/dispatcher/dispatcher.py b/aiogram/dispatcher/dispatcher.py
index ef707a6a..06cce1b1 100644
--- a/aiogram/dispatcher/dispatcher.py
+++ b/aiogram/dispatcher/dispatcher.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import asyncio
 import contextvars
 import warnings
@@ -96,7 +98,7 @@ class Dispatcher(Router):
                 update_id = update.update_id + 1
 
     @classmethod
-    async def _silent_call_request(cls, bot: Bot, result: TelegramMethod) -> None:
+    async def _silent_call_request(cls, bot: Bot, result: TelegramMethod[Any]) -> None:
         """
         Simulate answer into WebHook
 
@@ -172,7 +174,7 @@ class Dispatcher(Router):
             raise
 
     async def feed_webhook_update(
-        self, bot: Bot, update: Union[Update, Dict[str, Any]], _timeout: int = 55, **kwargs
+        self, bot: Bot, update: Union[Update, Dict[str, Any]], _timeout: int = 55, **kwargs: Any
     ) -> Optional[Dict[str, Any]]:
         if not isinstance(update, Update):  # Allow to use raw updates
             update = Update(**update)
@@ -181,18 +183,18 @@ class Dispatcher(Router):
         loop = asyncio.get_running_loop()
         waiter = loop.create_future()
 
-        def release_waiter(*args: Any):
+        def release_waiter(*args: Any) -> None:
             if not waiter.done():
                 waiter.set_result(None)
 
         timeout_handle = loop.call_later(_timeout, release_waiter)
 
-        process_updates: Future = asyncio.ensure_future(
+        process_updates: Future[Any] = asyncio.ensure_future(
             self._feed_webhook_update(bot=bot, update=update, **kwargs)
         )
         process_updates.add_done_callback(release_waiter, context=ctx)
 
-        def process_response(task: Future):
+        def process_response(task: Future[Any]) -> None:
             warnings.warn(
                 f"Detected slow response into webhook.\n"
                 f"Telegram is waiting for response only first 60 seconds and then re-send update.\n"
diff --git a/aiogram/dispatcher/event/handler.py b/aiogram/dispatcher/event/handler.py
index 52e8c0da..fa24f259 100644
--- a/aiogram/dispatcher/event/handler.py
+++ b/aiogram/dispatcher/event/handler.py
@@ -1,7 +1,16 @@
 import inspect
 from dataclasses import dataclass, field
 from functools import partial
-from typing import Any, Awaitable, Callable, Dict, List, Optional, Tuple, Union
+from typing import (
+    Any,
+    Awaitable,
+    Callable,
+    Dict,
+    List,
+    Optional,
+    Tuple,
+    Union,
+)
 
 from aiogram.dispatcher.filters.base import BaseFilter
 from aiogram.dispatcher.handler.base import BaseHandler
@@ -19,21 +28,22 @@ class CallableMixin:
     awaitable: bool = field(init=False)
     spec: inspect.FullArgSpec = field(init=False)
 
-    def __post_init__(self):
+    def __post_init__(self) -> None:
         callback = self.callback
         self.awaitable = inspect.isawaitable(callback) or inspect.iscoroutinefunction(callback)
         while hasattr(callback, "__wrapped__"):  # Try to resolve decorated callbacks
-            callback = callback.__wrapped__
+            callback = callback.__wrapped__  # type: ignore
         self.spec = inspect.getfullargspec(callback)
 
-    def _prepare_kwargs(self, kwargs):
+    def _prepare_kwargs(self, kwargs: Dict[str, Any]) -> Dict[str, Any]:
         if self.spec.varkw:
             return kwargs
 
         return {k: v for k, v in kwargs.items() if k in self.spec.args}
 
-    async def call(self, *args, **kwargs):
-        wrapped = partial(self.callback, *args, **self._prepare_kwargs(kwargs))
+    async def call(self, *args: Any, **kwargs: Any) -> Any:
+        # TODO: what we should do if callback is BaseHandler?
+        wrapped = partial(self.callback, *args, **self._prepare_kwargs(kwargs))  # type: ignore
         if self.awaitable:
             return await wrapped()
         return wrapped()
@@ -49,10 +59,10 @@ class HandlerObject(CallableMixin):
     callback: HandlerType
     filters: Optional[List[FilterObject]] = None
 
-    def __post_init__(self):
+    def __post_init__(self) -> None:
         super(HandlerObject, self).__post_init__()
-
-        if inspect.isclass(self.callback) and issubclass(self.callback, BaseHandler):
+        # TODO: by types callback must be Callable or BaseHandler, not Type[BaseHandler]
+        if inspect.isclass(self.callback) and issubclass(self.callback, BaseHandler):  # type: ignore
             self.awaitable = True
 
     async def check(self, *args: Any, **kwargs: Any) -> Tuple[bool, Dict[str, Any]]:
diff --git a/aiogram/dispatcher/filters/__init__.py b/aiogram/dispatcher/filters/__init__.py
index 21fb80c3..3baca36f 100644
--- a/aiogram/dispatcher/filters/__init__.py
+++ b/aiogram/dispatcher/filters/__init__.py
@@ -1,4 +1,8 @@
-from typing import Dict, Tuple, Union
+from typing import (
+    Dict,
+    Tuple,
+    Type,
+)
 
 from .base import BaseFilter
 from .command import Command, CommandObject
@@ -14,7 +18,7 @@ __all__ = (
     "ContentTypesFilter",
 )
 
-BUILTIN_FILTERS: Dict[str, Union[Tuple[BaseFilter], Tuple]] = {
+BUILTIN_FILTERS: Dict[str, Tuple[Type[BaseFilter], ...]] = {
     "update": (),
     "message": (Text, Command, ContentTypesFilter),
     "edited_message": (Text, Command, ContentTypesFilter),
diff --git a/aiogram/dispatcher/filters/base.py b/aiogram/dispatcher/filters/base.py
index c0a6c377..8d226720 100644
--- a/aiogram/dispatcher/filters/base.py
+++ b/aiogram/dispatcher/filters/base.py
@@ -1,22 +1,26 @@
 from abc import ABC, abstractmethod
-from typing import TYPE_CHECKING, Any, Dict, Union
+from typing import (
+    Awaitable,
+    Callable,
+    Any,
+    Dict,
+    Union,
+)
 
 from pydantic import BaseModel
 
 
+async def _call_for_override(*args: Any, **kwargs: Any) -> Union[bool, Dict[str, Any]]:
+    pass
+
+
 class BaseFilter(ABC, BaseModel):
-    if TYPE_CHECKING:  # pragma: no cover
-        # This checking type-hint is needed because mypy checks validity of overrides and raises:
-        # error: Signature of "__call__" incompatible with supertype "BaseFilter"  [override]
-        # https://mypy.readthedocs.io/en/latest/error_code_list.html#check-validity-of-overrides-override
+    # This little hack with typehint is needed because mypy checks validity of overrides and raises:
+    # error: Signature of "__call__" incompatible with supertype "BaseFilter"  [override]
+    # https://mypy.readthedocs.io/en/latest/error_code_list.html#check-validity-of-overrides-override
+    __call__: Callable[..., Awaitable[Union[bool, Dict[str, Any]]]] = _call_for_override
+    abstractmethod(__call__)
 
-        pass
-    else:  # pragma: no cover
-
-        @abstractmethod
-        async def __call__(self, *args: Any, **kwargs: Any) -> Union[bool, Dict[str, Any]]:
-            pass
-
-    def __await__(self):  # pragma: no cover
+    def __await__(self):  # type: ignore  # pragma: no cover
         # Is needed only for inspection and this method is never be called
         return self.__call__
diff --git a/aiogram/dispatcher/filters/command.py b/aiogram/dispatcher/filters/command.py
index 0fa49b30..7d0c05f8 100644
--- a/aiogram/dispatcher/filters/command.py
+++ b/aiogram/dispatcher/filters/command.py
@@ -10,7 +10,7 @@ from aiogram import Bot
 from aiogram.api.types import Message
 from aiogram.dispatcher.filters import BaseFilter
 
-CommandPatterType = Union[str, re.Pattern]  # type: ignore
+CommandPatterType = Union[str, re.Pattern]
 
 
 class Command(BaseFilter):
diff --git a/aiogram/dispatcher/filters/text.py b/aiogram/dispatcher/filters/text.py
index 8a94cd7b..8ab3822d 100644
--- a/aiogram/dispatcher/filters/text.py
+++ b/aiogram/dispatcher/filters/text.py
@@ -80,7 +80,7 @@ class Text(BaseFilter):
         # Impossible because the validator prevents this situation
         return False  # pragma: no cover
 
-    def prepare_text(self, text: str):
+    def prepare_text(self, text: str) -> str:
         if self.text_ignore_case:
             return str(text).lower()
         else:
diff --git a/aiogram/dispatcher/handler/base.py b/aiogram/dispatcher/handler/base.py
index d4ce4c53..21bc248b 100644
--- a/aiogram/dispatcher/handler/base.py
+++ b/aiogram/dispatcher/handler/base.py
@@ -1,5 +1,13 @@
 from abc import ABC, abstractmethod
-from typing import TYPE_CHECKING, Any, Dict, Generic, TypeVar
+from typing import (
+    Optional,
+    TYPE_CHECKING,
+    Any,
+    Dict,
+    Generic,
+    TypeVar,
+    cast,
+)
 
 from aiogram import Bot
 from aiogram.api.types import Update
@@ -23,18 +31,20 @@ class BaseHandler(BaseHandlerMixin[T], ABC):
         self.data: Dict[str, Any] = kwargs
 
     @property
-    def bot(self) -> Bot:
+    def bot(self) -> Optional[Bot]:
         if "bot" in self.data:
-            return self.data["bot"]
+            # TODO: remove cast
+            return cast(Bot, self.data["bot"])
         return Bot.get_current()
 
     @property
     def update(self) -> Update:
-        return self.data["update"]
+        # TODO: remove cast
+        return cast(Update, self.data["update"])
 
     @abstractmethod
     async def handle(self) -> Any:  # pragma: no cover
         pass
 
-    def __await__(self):
+    def __await__(self) -> Any:
         return self.handle().__await__()
diff --git a/aiogram/dispatcher/handler/message.py b/aiogram/dispatcher/handler/message.py
index d881a75b..47ad54f3 100644
--- a/aiogram/dispatcher/handler/message.py
+++ b/aiogram/dispatcher/handler/message.py
@@ -1,5 +1,8 @@
 from abc import ABC
-from typing import Optional
+from typing import (
+    Optional,
+    cast,
+)
 
 from aiogram.api.types import Chat, Message, User
 from aiogram.dispatcher.filters import CommandObject
@@ -24,5 +27,6 @@ class MessageHandlerCommandMixin(BaseHandlerMixin[Message]):
     @property
     def command(self) -> Optional[CommandObject]:
         if "command" in self.data:
-            return self.data["command"]
+            # TODO: remove cast
+            return cast(CommandObject, self.data["command"])
         return None
diff --git a/aiogram/dispatcher/router.py b/aiogram/dispatcher/router.py
index 3bf5dd27..44a47255 100644
--- a/aiogram/dispatcher/router.py
+++ b/aiogram/dispatcher/router.py
@@ -3,7 +3,12 @@ from __future__ import annotations
 import warnings
 from typing import Any, Dict, List, Optional, Union
 
-from ..api.types import Chat, Update, User
+from ..api.types import (
+    Chat,
+    TelegramObject,
+    Update,
+    User,
+)
 from ..utils.imports import import_module
 from ..utils.warnings import CodeHasNoEffect
 from .event.observer import EventObserver, SkipHandler, TelegramEventObserver
@@ -151,6 +156,7 @@ class Router:
         chat: Optional[Chat] = None
         from_user: Optional[User] = None
 
+        event: TelegramObject
         if update.message:
             update_type = "message"
             from_user = update.message.from_user
@@ -211,7 +217,7 @@ class Router:
 
         raise SkipHandler
 
-    async def emit_startup(self, *args, **kwargs) -> None:
+    async def emit_startup(self, *args: Any, **kwargs: Any) -> None:
         """
         Recursively call startup callbacks
 
@@ -225,7 +231,7 @@ class Router:
         for router in self.sub_routers:
             await router.emit_startup(*args, **kwargs)
 
-    async def emit_shutdown(self, *args, **kwargs) -> None:
+    async def emit_shutdown(self, *args: Any, **kwargs: Any) -> None:
         """
         Recursively call shutdown callbacks to graceful shutdown
 
diff --git a/aiogram/utils/helper.py b/aiogram/utils/helper.py
index fbb1524b..87ecfe04 100644
--- a/aiogram/utils/helper.py
+++ b/aiogram/utils/helper.py
@@ -13,7 +13,15 @@ Example:
     >>> print(MyHelper.all())
     <<<  ['barItem', 'bazItem', 'fooItem', 'lorem']
 """
-from typing import List
+from typing import (
+    Any,
+    Callable,
+    Iterable,
+    List,
+    Optional,
+    Union,
+    cast,
+)
 
 PROPS_KEYS_ATTR_NAME = "_props_keys"
 
@@ -22,12 +30,12 @@ class Helper:
     mode = ""
 
     @classmethod
-    def all(cls):
+    def all(cls) -> List[Any]:
         """
         Get all consts
         :return: list
         """
-        result = []
+        result: List[Any] = []
         for name in dir(cls):
             if not name.isupper():
                 continue
@@ -49,7 +57,7 @@ class HelperMode(Helper):
     lowercase = "lowercase"
 
     @classmethod
-    def all(cls):
+    def all(cls) -> List[str]:
         return [
             cls.SCREAMING_SNAKE_CASE,
             cls.lowerCamelCase,
@@ -59,7 +67,7 @@ class HelperMode(Helper):
         ]
 
     @classmethod
-    def _screaming_snake_case(cls, text):
+    def _screaming_snake_case(cls, text: str) -> str:
         """
         Transform text to SCREAMING_SNAKE_CASE
 
@@ -77,7 +85,7 @@ class HelperMode(Helper):
         return result
 
     @classmethod
-    def _snake_case(cls, text):
+    def _snake_case(cls, text: str) -> str:
         """
         Transform text to snake case (Based on SCREAMING_SNAKE_CASE)
 
@@ -89,7 +97,7 @@ class HelperMode(Helper):
         return cls._screaming_snake_case(text).lower()
 
     @classmethod
-    def _camel_case(cls, text, first_upper=False):
+    def _camel_case(cls, text: str, first_upper: bool = False) -> str:
         """
         Transform text to camelCase or CamelCase
 
@@ -113,7 +121,7 @@ class HelperMode(Helper):
         return result
 
     @classmethod
-    def apply(cls, text, mode):
+    def apply(cls, text: str, mode: Union[str, Callable[[str], str]]) -> str:
         """
         Apply mode for text
 
@@ -136,7 +144,20 @@ class HelperMode(Helper):
         return text
 
 
-class Item:
+class _BaseItem:
+    def __init__(self, value: Optional[str] = None):
+        self._value = cast(str, value)
+
+    def __set_name__(self, owner: Any, name: str) -> None:
+        if not name.isupper():
+            raise NameError("Name for helper item must be in uppercase!")
+        if not self._value:
+            # TODO: а если не имеет?
+            if hasattr(owner, "mode"):
+                self._value = HelperMode.apply(name, getattr(owner, "mode"))
+
+
+class Item(_BaseItem):
     """
     Helper item
 
@@ -144,34 +165,24 @@ class Item:
     it will be automatically generated based on a variable's name
     """
 
-    def __init__(self, value=None):
-        self._value = value
-
-    def __get__(self, instance, owner):
+    def __get__(self, instance: Any, owner: Any) -> str:
         return self._value
 
-    def __set_name__(self, owner, name):
-        if not name.isupper():
-            raise NameError("Name for helper item must be in uppercase!")
-        if not self._value:
-            if hasattr(owner, "mode"):
-                self._value = HelperMode.apply(name, getattr(owner, "mode"))
 
-
-class ListItem(Item):
+class ListItem(_BaseItem):
     """
     This item is always a list
 
     You can use &, | and + operators for that.
     """
 
-    def add(self, other):  # pragma: no cover
+    def add(self, other: "ListItem") -> "ListItem":  # pragma: no cover
         return self + other
 
-    def __get__(self, instance, owner):
+    def __get__(self, instance: Any, owner: Any) -> "ItemsList":
         return ItemsList(self._value)
 
-    def __getitem__(self, item):  # pragma: no cover
+    def __getitem__(self, item: Any) -> Any:  # pragma: no cover
         # Only for IDE. This method is never be called.
         return self._value
 
@@ -179,17 +190,17 @@ class ListItem(Item):
     __iadd__ = __add__ = __rand__ = __and__ = __ror__ = __or__ = add
 
 
-class ItemsList(list):
+class ItemsList(List[str]):
     """
     Patch for default list
 
     This class provides +, &, |, +=, &=, |= operators for extending the list
     """
 
-    def __init__(self, *seq):
+    def __init__(self, *seq: Any):
         super(ItemsList, self).__init__(map(str, seq))
 
-    def add(self, other):
+    def add(self, other: Iterable[str]) -> "ItemsList":
         self.extend(other)
         return self
 
@@ -197,7 +208,7 @@ class ItemsList(list):
 
 
 class OrderedHelperMeta(type):
-    def __new__(mcs, name, bases, namespace, **kwargs):
+    def __new__(mcs, name: Any, bases: Any, namespace: Any, **kwargs: Any) -> "OrderedHelperMeta":
         cls = super().__new__(mcs, name, bases, namespace)
 
         props_keys = []
@@ -209,7 +220,8 @@ class OrderedHelperMeta(type):
 
         setattr(cls, PROPS_KEYS_ATTR_NAME, props_keys)
 
-        return cls
+        # ref: https://gitter.im/python/typing?at=5da98cc5fa637359fc9cbfe1
+        return cast(OrderedHelperMeta, cls)
 
 
 class OrderedHelper(metaclass=OrderedHelperMeta):
diff --git a/aiogram/utils/mixins.py b/aiogram/utils/mixins.py
index ca17b8d8..719cfaed 100644
--- a/aiogram/utils/mixins.py
+++ b/aiogram/utils/mixins.py
@@ -1,51 +1,64 @@
+from __future__ import annotations
 import contextvars
-from typing import Type, TypeVar
+from typing import (
+    Any,
+    ClassVar,
+    Generic,
+    Optional,
+    TypeVar,
+    cast,
+    overload,
+)
 
-__all__ = ("DataMixin", "ContextInstanceMixin")
+__all__ = ("ContextInstanceMixin",)
+
+from typing_extensions import Literal
 
 
-class DataMixin:
-    @property
-    def data(self):
-        data = getattr(self, "_data", None)
-        if data is None:
-            data = {}
-            setattr(self, "_data", data)
-        return data
-
-    def __getitem__(self, item):
-        return self.data[item]
-
-    def __setitem__(self, key, value):
-        self.data[key] = value
-
-    def __delitem__(self, key):
-        del self.data[key]
-
-    def __contains__(self, item):
-        return item in self.data
-
-    def get(self, key, default=None):
-        return self.data.get(key, default)
+ContextInstance = TypeVar("ContextInstance")
 
 
-T = TypeVar("T")
+class ContextInstanceMixin(Generic[ContextInstance]):
+    __context_instance: ClassVar[contextvars.ContextVar[ContextInstance]]
 
-
-class ContextInstanceMixin:
-    def __init_subclass__(cls, **kwargs):
-        super().__init_subclass__(**kwargs)
+    def __init_subclass__(cls, **kwargs: Any) -> None:
+        super().__init_subclass__()
         cls.__context_instance = contextvars.ContextVar(f"instance_{cls.__name__}")
-        return cls
+
+    @overload
+    @classmethod
+    def get_current(cls) -> Optional[ContextInstance]:
+        ...
+
+    @overload  # noqa: F811, it's overload, not redefinition
+    @classmethod
+    def get_current(cls, no_error: Literal[True]) -> Optional[ContextInstance]:
+        ...
+
+    @overload   # noqa: F811, it's overload, not redefinition
+    @classmethod
+    def get_current(cls, no_error: Literal[False]) -> ContextInstance:
+        ...
+
+    @classmethod  # noqa: F811, it's overload, not redefinition
+    def get_current(cls, no_error: bool = True) -> Optional[ContextInstance]:
+        # on mypy 0.770 I catch that contextvars.ContextVar always contextvars.ContextVar[Any]
+        cls.__context_instance = cast(
+            contextvars.ContextVar[ContextInstance], cls.__context_instance
+        )
+
+        try:
+            current: Optional[ContextInstance] = cls.__context_instance.get()
+        except LookupError:
+            if no_error:
+                current = None
+            else:
+                raise
+
+        return current
 
     @classmethod
-    def get_current(cls: Type[T], no_error=True) -> T:
-        if no_error:
-            return cls.__context_instance.get(None)
-        return cls.__context_instance.get()
-
-    @classmethod
-    def set_current(cls: Type[T], value: T) -> contextvars.Token:
+    def set_current(cls, value: ContextInstance) -> contextvars.Token[ContextInstance]:
         if not isinstance(value, cls):
             raise TypeError(
                 f"Value should be instance of {cls.__name__!r} not {type(value).__name__!r}"
@@ -53,5 +66,5 @@ class ContextInstanceMixin:
         return cls.__context_instance.set(value)
 
     @classmethod
-    def reset_current(cls: Type[T], token: contextvars.Token):
+    def reset_current(cls, token: contextvars.Token[ContextInstance]) -> None:
         cls.__context_instance.reset(token)
diff --git a/mypy.ini b/mypy.ini
index d4a3381e..7cbf0ca4 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -1,6 +1,21 @@
 [mypy]
-# plugins = pydantic.mypy
-
+;plugins = pydantic.mypy
+;python_version = 3.8
+warn_unused_configs = True
+disallow_subclassing_any = True
+disallow_any_generics = True
+disallow_untyped_calls = True
+disallow_untyped_defs = True
+disallow_incomplete_defs = True
+check_untyped_defs = True
+disallow_untyped_decorators = True
+no_implicit_optional = True
+warn_redundant_casts = True
+warn_unused_ignores = True
+warn_return_any = True
+follow_imports_for_stubs = True
+namespace_packages = True
+show_absolute_path = True
 ignore_missing_imports = True
 show_error_context = True
 show_error_codes = True
diff --git a/poetry.lock b/poetry.lock
index f1088435..f20ab5b1 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -153,8 +153,8 @@ category = "dev"
 description = "Composable command line interface toolkit"
 name = "click"
 optional = false
-python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
-version = "7.0"
+python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*"
+version = "7.1.1"
 
 [[package]]
 category = "dev"
@@ -171,7 +171,7 @@ description = "Code coverage measurement for Python"
 name = "coverage"
 optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, <4"
-version = "5.0.3"
+version = "5.0.4"
 
 [package.extras]
 toml = ["toml"]
@@ -182,7 +182,7 @@ description = "Decorators for Humans"
 name = "decorator"
 optional = false
 python-versions = ">=2.6, !=3.0.*, !=3.1.*"
-version = "4.4.1"
+version = "4.4.2"
 
 [[package]]
 category = "dev"
@@ -219,6 +219,14 @@ flake8 = ">=3.3.0"
 jinja2 = ">=2.9.0"
 pygments = ">=2.2.0"
 
+[[package]]
+category = "dev"
+description = "Clean single-source support for Python 3 and 2"
+name = "future"
+optional = false
+python-versions = ">=2.6, !=3.0.*, !=3.1.*, !=3.2.*"
+version = "0.18.2"
+
 [[package]]
 category = "main"
 description = "Internationalized Domain Names in Applications (IDNA)"
@@ -249,7 +257,7 @@ description = "IPython: Productive Interactive Computing"
 name = "ipython"
 optional = false
 python-versions = ">=3.6"
-version = "7.12.0"
+version = "7.13.0"
 
 [package.dependencies]
 appnope = "*"
@@ -265,7 +273,7 @@ setuptools = ">=18.5"
 traitlets = ">=4.2"
 
 [package.extras]
-all = ["ipyparallel", "requests", "notebook", "qtconsole", "ipywidgets", "pygments", "nbconvert", "testpath", "Sphinx (>=1.3)", "nbformat", "numpy (>=1.14)", "ipykernel", "nose (>=0.10.1)"]
+all = ["numpy (>=1.14)", "testpath", "notebook", "nose (>=0.10.1)", "nbconvert", "requests", "ipywidgets", "qtconsole", "ipyparallel", "Sphinx (>=1.3)", "pygments", "nbformat", "ipykernel"]
 doc = ["Sphinx (>=1.3)"]
 kernel = ["ipykernel"]
 nbconvert = ["nbconvert"]
@@ -338,6 +346,25 @@ version = "2.6.1"
 six = "*"
 tornado = "*"
 
+[[package]]
+category = "dev"
+description = "A Python implementation of Lunr.js"
+name = "lunr"
+optional = false
+python-versions = "*"
+version = "0.5.6"
+
+[package.dependencies]
+future = ">=0.16.0"
+six = ">=1.11.0"
+
+[package.dependencies.nltk]
+optional = true
+version = ">=3.2.5"
+
+[package.extras]
+languages = ["nltk (>=3.2.5)"]
+
 [[package]]
 category = "dev"
 description = "Powerful and Pythonic XML processing library combining libxml2/libxslt with the ElementTree API."
@@ -406,17 +433,21 @@ category = "dev"
 description = "Project documentation with Markdown."
 name = "mkdocs"
 optional = false
-python-versions = ">=2.7.9,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*"
-version = "1.0.4"
+python-versions = ">=3.5"
+version = "1.1"
 
 [package.dependencies]
-Jinja2 = ">=2.7.1"
-Markdown = ">=2.3.1"
+Jinja2 = ">=2.10.1"
+Markdown = ">=3.2.1"
 PyYAML = ">=3.10"
 click = ">=3.3"
 livereload = ">=2.5.1"
 tornado = ">=5.0"
 
+[package.dependencies.lunr]
+extras = ["languages"]
+version = "0.5.6"
+
 [[package]]
 category = "dev"
 description = "A Material Design theme for MkDocs"
@@ -453,7 +484,7 @@ description = "Optional static typing for Python"
 name = "mypy"
 optional = false
 python-versions = ">=3.5"
-version = "0.761"
+version = "0.770"
 
 [package.dependencies]
 mypy-extensions = ">=0.4.3,<0.5.0"
@@ -471,13 +502,32 @@ optional = false
 python-versions = "*"
 version = "0.4.3"
 
+[[package]]
+category = "dev"
+description = "Natural Language Toolkit"
+name = "nltk"
+optional = false
+python-versions = "*"
+version = "3.4.5"
+
+[package.dependencies]
+six = "*"
+
+[package.extras]
+all = ["pyparsing", "scikit-learn", "python-crfsuite", "matplotlib", "scipy", "gensim", "requests", "twython", "numpy"]
+corenlp = ["requests"]
+machine_learning = ["gensim", "numpy", "python-crfsuite", "scikit-learn", "scipy"]
+plot = ["matplotlib"]
+tgrep = ["pyparsing"]
+twitter = ["twython"]
+
 [[package]]
 category = "dev"
 description = "Core utilities for Python packages"
 name = "packaging"
 optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
-version = "20.1"
+version = "20.3"
 
 [package.dependencies]
 pyparsing = ">=2.0.2"
@@ -489,7 +539,7 @@ description = "A Python Parser"
 name = "parso"
 optional = false
 python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*"
-version = "0.6.1"
+version = "0.6.2"
 
 [package.extras]
 testing = ["docopt", "pytest (>=3.0.7)"]
@@ -543,8 +593,8 @@ category = "dev"
 description = "Library for building powerful interactive command lines in Python"
 name = "prompt-toolkit"
 optional = false
-python-versions = ">=3.6"
-version = "3.0.3"
+python-versions = ">=3.6.1"
+version = "3.0.4"
 
 [package.dependencies]
 wcwidth = "*"
@@ -600,8 +650,8 @@ category = "dev"
 description = "Pygments is a syntax highlighting package written in Python."
 name = "pygments"
 optional = false
-python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*"
-version = "2.5.2"
+python-versions = ">=3.5"
+version = "2.6.1"
 
 [[package]]
 category = "dev"
@@ -628,7 +678,7 @@ description = "pytest: simple powerful testing with Python"
 name = "pytest"
 optional = false
 python-versions = ">=3.5"
-version = "5.3.5"
+version = "5.4.1"
 
 [package.dependencies]
 atomicwrites = ">=1.0"
@@ -683,7 +733,7 @@ description = "pytest plugin for generating HTML reports"
 name = "pytest-html"
 optional = false
 python-versions = ">=3.6"
-version = "2.0.1"
+version = "2.1.0"
 
 [package.dependencies]
 pytest = ">=5.0"
@@ -781,7 +831,7 @@ description = "Tornado is a Python web framework and asynchronous networking lib
 name = "tornado"
 optional = false
 python-versions = ">= 3.5"
-version = "6.0.3"
+version = "6.0.4"
 
 [[package]]
 category = "dev"
@@ -851,7 +901,7 @@ marker = "python_version >= \"3.5\" and python_version < \"3.8\" or python_versi
 name = "zipp"
 optional = false
 python-versions = ">=3.6"
-version = "3.0.0"
+version = "3.1.0"
 
 [package.extras]
 docs = ["sphinx", "jaraco.packaging (>=3.2)", "rst.linker (>=1.9)"]
@@ -861,7 +911,7 @@ testing = ["jaraco.itertools", "func-timeout"]
 fast = ["uvloop"]
 
 [metadata]
-content-hash = "2eb50b5b57d0fac4780f1eb3f92ff129d891fd346e0c00856c1a56c58feffb03"
+content-hash = "bce1bc7bf9eb949283094490a084d484a3d2f7b0d992ea3a4ea1e75401f6e2da"
 python-versions = "^3.7"
 
 [metadata.files]
@@ -931,49 +981,49 @@ chardet = [
     {file = "chardet-3.0.4.tar.gz", hash = "sha256:84ab92ed1c4d4f16916e05906b6b75a6c0fb5db821cc65e70cbd64a3e2a5eaae"},
 ]
 click = [
-    {file = "Click-7.0-py2.py3-none-any.whl", hash = "sha256:2335065e6395b9e67ca716de5f7526736bfa6ceead690adf616d925bdc622b13"},
-    {file = "Click-7.0.tar.gz", hash = "sha256:5b94b49521f6456670fdb30cd82a4eca9412788a93fa6dd6df72c94d5a8ff2d7"},
+    {file = "click-7.1.1-py2.py3-none-any.whl", hash = "sha256:e345d143d80bf5ee7534056164e5e112ea5e22716bbb1ce727941f4c8b471b9a"},
+    {file = "click-7.1.1.tar.gz", hash = "sha256:8a18b4ea89d8820c5d0c7da8a64b2c324b4dabb695804dbfea19b9be9d88c0cc"},
 ]
 colorama = [
     {file = "colorama-0.4.3-py2.py3-none-any.whl", hash = "sha256:7d73d2a99753107a36ac6b455ee49046802e59d9d076ef8e47b61499fa29afff"},
     {file = "colorama-0.4.3.tar.gz", hash = "sha256:e96da0d330793e2cb9485e9ddfd918d456036c7149416295932478192f4436a1"},
 ]
 coverage = [
-    {file = "coverage-5.0.3-cp27-cp27m-macosx_10_12_x86_64.whl", hash = "sha256:cc1109f54a14d940b8512ee9f1c3975c181bbb200306c6d8b87d93376538782f"},
-    {file = "coverage-5.0.3-cp27-cp27m-macosx_10_13_intel.whl", hash = "sha256:be18f4ae5a9e46edae3f329de2191747966a34a3d93046dbdf897319923923bc"},
-    {file = "coverage-5.0.3-cp27-cp27m-manylinux1_i686.whl", hash = "sha256:3230d1003eec018ad4a472d254991e34241e0bbd513e97a29727c7c2f637bd2a"},
-    {file = "coverage-5.0.3-cp27-cp27m-manylinux1_x86_64.whl", hash = "sha256:e69215621707119c6baf99bda014a45b999d37602cb7043d943c76a59b05bf52"},
-    {file = "coverage-5.0.3-cp27-cp27m-win32.whl", hash = "sha256:1daa3eceed220f9fdb80d5ff950dd95112cd27f70d004c7918ca6dfc6c47054c"},
-    {file = "coverage-5.0.3-cp27-cp27m-win_amd64.whl", hash = "sha256:51bc7710b13a2ae0c726f69756cf7ffd4362f4ac36546e243136187cfcc8aa73"},
-    {file = "coverage-5.0.3-cp27-cp27mu-manylinux1_i686.whl", hash = "sha256:9bea19ac2f08672636350f203db89382121c9c2ade85d945953ef3c8cf9d2a68"},
-    {file = "coverage-5.0.3-cp27-cp27mu-manylinux1_x86_64.whl", hash = "sha256:5012d3b8d5a500834783689a5d2292fe06ec75dc86ee1ccdad04b6f5bf231691"},
-    {file = "coverage-5.0.3-cp35-cp35m-macosx_10_12_x86_64.whl", hash = "sha256:d513cc3db248e566e07a0da99c230aca3556d9b09ed02f420664e2da97eac301"},
-    {file = "coverage-5.0.3-cp35-cp35m-manylinux1_i686.whl", hash = "sha256:3dbb72eaeea5763676a1a1efd9b427a048c97c39ed92e13336e726117d0b72bf"},
-    {file = "coverage-5.0.3-cp35-cp35m-manylinux1_x86_64.whl", hash = "sha256:15cf13a6896048d6d947bf7d222f36e4809ab926894beb748fc9caa14605d9c3"},
-    {file = "coverage-5.0.3-cp35-cp35m-win32.whl", hash = "sha256:fca1669d464f0c9831fd10be2eef6b86f5ebd76c724d1e0706ebdff86bb4adf0"},
-    {file = "coverage-5.0.3-cp35-cp35m-win_amd64.whl", hash = "sha256:1e44a022500d944d42f94df76727ba3fc0a5c0b672c358b61067abb88caee7a0"},
-    {file = "coverage-5.0.3-cp36-cp36m-macosx_10_13_x86_64.whl", hash = "sha256:b26aaf69713e5674efbde4d728fb7124e429c9466aeaf5f4a7e9e699b12c9fe2"},
-    {file = "coverage-5.0.3-cp36-cp36m-manylinux1_i686.whl", hash = "sha256:722e4557c8039aad9592c6a4213db75da08c2cd9945320220634f637251c3894"},
-    {file = "coverage-5.0.3-cp36-cp36m-manylinux1_x86_64.whl", hash = "sha256:7afad9835e7a651d3551eab18cbc0fdb888f0a6136169fbef0662d9cdc9987cf"},
-    {file = "coverage-5.0.3-cp36-cp36m-win32.whl", hash = "sha256:25dbf1110d70bab68a74b4b9d74f30e99b177cde3388e07cc7272f2168bd1477"},
-    {file = "coverage-5.0.3-cp36-cp36m-win_amd64.whl", hash = "sha256:c312e57847db2526bc92b9bfa78266bfbaabac3fdcd751df4d062cd4c23e46dc"},
-    {file = "coverage-5.0.3-cp37-cp37m-macosx_10_13_x86_64.whl", hash = "sha256:a8b8ac7876bc3598e43e2603f772d2353d9931709345ad6c1149009fd1bc81b8"},
-    {file = "coverage-5.0.3-cp37-cp37m-manylinux1_i686.whl", hash = "sha256:527b4f316e6bf7755082a783726da20671a0cc388b786a64417780b90565b987"},
-    {file = "coverage-5.0.3-cp37-cp37m-manylinux1_x86_64.whl", hash = "sha256:d649dc0bcace6fcdb446ae02b98798a856593b19b637c1b9af8edadf2b150bea"},
-    {file = "coverage-5.0.3-cp37-cp37m-win32.whl", hash = "sha256:cd60f507c125ac0ad83f05803063bed27e50fa903b9c2cfee3f8a6867ca600fc"},
-    {file = "coverage-5.0.3-cp37-cp37m-win_amd64.whl", hash = "sha256:c60097190fe9dc2b329a0eb03393e2e0829156a589bd732e70794c0dd804258e"},
-    {file = "coverage-5.0.3-cp38-cp38-macosx_10_13_x86_64.whl", hash = "sha256:d7008a6796095a79544f4da1ee49418901961c97ca9e9d44904205ff7d6aa8cb"},
-    {file = "coverage-5.0.3-cp38-cp38-manylinux1_i686.whl", hash = "sha256:ea9525e0fef2de9208250d6c5aeeee0138921057cd67fcef90fbed49c4d62d37"},
-    {file = "coverage-5.0.3-cp38-cp38-manylinux1_x86_64.whl", hash = "sha256:c62a2143e1313944bf4a5ab34fd3b4be15367a02e9478b0ce800cb510e3bbb9d"},
-    {file = "coverage-5.0.3-cp38-cp38m-win32.whl", hash = "sha256:b0840b45187699affd4c6588286d429cd79a99d509fe3de0f209594669bb0954"},
-    {file = "coverage-5.0.3-cp38-cp38m-win_amd64.whl", hash = "sha256:76e2057e8ffba5472fd28a3a010431fd9e928885ff480cb278877c6e9943cc2e"},
-    {file = "coverage-5.0.3-cp39-cp39m-win32.whl", hash = "sha256:b63dd43f455ba878e5e9f80ba4f748c0a2156dde6e0e6e690310e24d6e8caf40"},
-    {file = "coverage-5.0.3-cp39-cp39m-win_amd64.whl", hash = "sha256:da93027835164b8223e8e5af2cf902a4c80ed93cb0909417234f4a9df3bcd9af"},
-    {file = "coverage-5.0.3.tar.gz", hash = "sha256:77afca04240c40450c331fa796b3eab6f1e15c5ecf8bf2b8bee9706cd5452fef"},
+    {file = "coverage-5.0.4-cp27-cp27m-macosx_10_12_x86_64.whl", hash = "sha256:8a620767b8209f3446197c0e29ba895d75a1e272a36af0786ec70fe7834e4307"},
+    {file = "coverage-5.0.4-cp27-cp27m-macosx_10_13_intel.whl", hash = "sha256:73aa6e86034dad9f00f4bbf5a666a889d17d79db73bc5af04abd6c20a014d9c8"},
+    {file = "coverage-5.0.4-cp27-cp27m-manylinux1_i686.whl", hash = "sha256:408ce64078398b2ee2ec08199ea3fcf382828d2f8a19c5a5ba2946fe5ddc6c31"},
+    {file = "coverage-5.0.4-cp27-cp27m-manylinux1_x86_64.whl", hash = "sha256:cda33311cb9fb9323958a69499a667bd728a39a7aa4718d7622597a44c4f1441"},
+    {file = "coverage-5.0.4-cp27-cp27m-win32.whl", hash = "sha256:5f587dfd83cb669933186661a351ad6fc7166273bc3e3a1531ec5c783d997aac"},
+    {file = "coverage-5.0.4-cp27-cp27m-win_amd64.whl", hash = "sha256:9fad78c13e71546a76c2f8789623eec8e499f8d2d799f4b4547162ce0a4df435"},
+    {file = "coverage-5.0.4-cp27-cp27mu-manylinux1_i686.whl", hash = "sha256:2e08c32cbede4a29e2a701822291ae2bc9b5220a971bba9d1e7615312efd3037"},
+    {file = "coverage-5.0.4-cp27-cp27mu-manylinux1_x86_64.whl", hash = "sha256:922fb9ef2c67c3ab20e22948dcfd783397e4c043a5c5fa5ff5e9df5529074b0a"},
+    {file = "coverage-5.0.4-cp35-cp35m-macosx_10_12_x86_64.whl", hash = "sha256:c3fc325ce4cbf902d05a80daa47b645d07e796a80682c1c5800d6ac5045193e5"},
+    {file = "coverage-5.0.4-cp35-cp35m-manylinux1_i686.whl", hash = "sha256:046a1a742e66d065d16fb564a26c2a15867f17695e7f3d358d7b1ad8a61bca30"},
+    {file = "coverage-5.0.4-cp35-cp35m-manylinux1_x86_64.whl", hash = "sha256:6ad6ca45e9e92c05295f638e78cd42bfaaf8ee07878c9ed73e93190b26c125f7"},
+    {file = "coverage-5.0.4-cp35-cp35m-win32.whl", hash = "sha256:eda55e6e9ea258f5e4add23bcf33dc53b2c319e70806e180aecbff8d90ea24de"},
+    {file = "coverage-5.0.4-cp35-cp35m-win_amd64.whl", hash = "sha256:4a8a259bf990044351baf69d3b23e575699dd60b18460c71e81dc565f5819ac1"},
+    {file = "coverage-5.0.4-cp36-cp36m-macosx_10_13_x86_64.whl", hash = "sha256:f372cdbb240e09ee855735b9d85e7f50730dcfb6296b74b95a3e5dea0615c4c1"},
+    {file = "coverage-5.0.4-cp36-cp36m-manylinux1_i686.whl", hash = "sha256:a37c6233b28e5bc340054cf6170e7090a4e85069513320275a4dc929144dccf0"},
+    {file = "coverage-5.0.4-cp36-cp36m-manylinux1_x86_64.whl", hash = "sha256:443be7602c790960b9514567917af538cac7807a7c0c0727c4d2bbd4014920fd"},
+    {file = "coverage-5.0.4-cp36-cp36m-win32.whl", hash = "sha256:165a48268bfb5a77e2d9dbb80de7ea917332a79c7adb747bd005b3a07ff8caf0"},
+    {file = "coverage-5.0.4-cp36-cp36m-win_amd64.whl", hash = "sha256:0a907199566269e1cfa304325cc3b45c72ae341fbb3253ddde19fa820ded7a8b"},
+    {file = "coverage-5.0.4-cp37-cp37m-macosx_10_13_x86_64.whl", hash = "sha256:513e6526e0082c59a984448f4104c9bf346c2da9961779ede1fc458e8e8a1f78"},
+    {file = "coverage-5.0.4-cp37-cp37m-manylinux1_i686.whl", hash = "sha256:3844c3dab800ca8536f75ae89f3cf566848a3eb2af4d9f7b1103b4f4f7a5dad6"},
+    {file = "coverage-5.0.4-cp37-cp37m-manylinux1_x86_64.whl", hash = "sha256:641e329e7f2c01531c45c687efcec8aeca2a78a4ff26d49184dce3d53fc35014"},
+    {file = "coverage-5.0.4-cp37-cp37m-win32.whl", hash = "sha256:db1d4e38c9b15be1521722e946ee24f6db95b189d1447fa9ff18dd16ba89f732"},
+    {file = "coverage-5.0.4-cp37-cp37m-win_amd64.whl", hash = "sha256:62061e87071497951155cbccee487980524d7abea647a1b2a6eb6b9647df9006"},
+    {file = "coverage-5.0.4-cp38-cp38-macosx_10_13_x86_64.whl", hash = "sha256:65a7e00c00472cd0f59ae09d2fb8a8aaae7f4a0cf54b2b74f3138d9f9ceb9cb2"},
+    {file = "coverage-5.0.4-cp38-cp38-manylinux1_i686.whl", hash = "sha256:1f66cf263ec77af5b8fe14ef14c5e46e2eb4a795ac495ad7c03adc72ae43fafe"},
+    {file = "coverage-5.0.4-cp38-cp38-manylinux1_x86_64.whl", hash = "sha256:85596aa5d9aac1bf39fe39d9fa1051b0f00823982a1de5766e35d495b4a36ca9"},
+    {file = "coverage-5.0.4-cp38-cp38-win32.whl", hash = "sha256:86a0ea78fd851b313b2e712266f663e13b6bc78c2fb260b079e8b67d970474b1"},
+    {file = "coverage-5.0.4-cp38-cp38-win_amd64.whl", hash = "sha256:03f630aba2b9b0d69871c2e8d23a69b7fe94a1e2f5f10df5049c0df99db639a0"},
+    {file = "coverage-5.0.4-cp39-cp39-win32.whl", hash = "sha256:7c9762f80a25d8d0e4ab3cb1af5d9dffbddb3ee5d21c43e3474c84bf5ff941f7"},
+    {file = "coverage-5.0.4-cp39-cp39-win_amd64.whl", hash = "sha256:4482f69e0701139d0f2c44f3c395d1d1d37abd81bfafbf9b6efbe2542679d892"},
+    {file = "coverage-5.0.4.tar.gz", hash = "sha256:1b60a95fc995649464e0cd48cecc8288bac5f4198f21d04b8229dc4097d76823"},
 ]
 decorator = [
-    {file = "decorator-4.4.1-py2.py3-none-any.whl", hash = "sha256:5d19b92a3c8f7f101c8dd86afd86b0f061a8ce4540ab8cd401fa2542756bce6d"},
-    {file = "decorator-4.4.1.tar.gz", hash = "sha256:54c38050039232e1db4ad7375cfce6748d7b41c29e95a081c8a6d2c30364a2ce"},
+    {file = "decorator-4.4.2-py2.py3-none-any.whl", hash = "sha256:41fa54c2a0cc4ba648be4fd43cff00aedf5b9465c9bf18d64325bc225f08f760"},
+    {file = "decorator-4.4.2.tar.gz", hash = "sha256:e3a62f0520172440ca0dcc823749319382e377f37f140a0b99ef45fecb84bfe7"},
 ]
 entrypoints = [
     {file = "entrypoints-0.3-py2.py3-none-any.whl", hash = "sha256:589f874b313739ad35be6e0cd7efde2a4e9b6fea91edcc34e58ecbb8dbe56d19"},
@@ -987,6 +1037,9 @@ flake8-html = [
     {file = "flake8-html-0.4.0.tar.gz", hash = "sha256:44bec37f142e97c4a5b2cf10efe24ed253617a9736878851a594d4763011e742"},
     {file = "flake8_html-0.4.0-py2.py3-none-any.whl", hash = "sha256:f372cd599ba9a374943eaa75a9cce30408cf4c0cc2251bc5194e6b0d3fc2bc3a"},
 ]
+future = [
+    {file = "future-0.18.2.tar.gz", hash = "sha256:b1bead90b70cf6ec3f0710ae53a525360fa360d306a86583adc6bf83a4db537d"},
+]
 idna = [
     {file = "idna-2.9-py2.py3-none-any.whl", hash = "sha256:a068a21ceac8a4d63dbfd964670474107f541babbd2250d61922f029858365fa"},
     {file = "idna-2.9.tar.gz", hash = "sha256:7588d1c14ae4c77d74036e8c22ff447b26d0fde8f007354fd48a7814db15b7cb"},
@@ -996,8 +1049,8 @@ importlib-metadata = [
     {file = "importlib_metadata-1.5.0.tar.gz", hash = "sha256:06f5b3a99029c7134207dd882428a66992a9de2bef7c2b699b5641f9886c3302"},
 ]
 ipython = [
-    {file = "ipython-7.12.0-py3-none-any.whl", hash = "sha256:f6689108b1734501d3b59c84427259fd5ac5141afe2e846cfa8598eb811886c9"},
-    {file = "ipython-7.12.0.tar.gz", hash = "sha256:d9459e7237e2e5858738ff9c3e26504b79899b58a6d49e574d352493d80684c6"},
+    {file = "ipython-7.13.0-py3-none-any.whl", hash = "sha256:eb8d075de37f678424527b5ef6ea23f7b80240ca031c2dd6de5879d687a65333"},
+    {file = "ipython-7.13.0.tar.gz", hash = "sha256:ca478e52ae1f88da0102360e57e528b92f3ae4316aabac80a2cd7f7ab2efb48a"},
 ]
 ipython-genutils = [
     {file = "ipython_genutils-0.2.0-py2.py3-none-any.whl", hash = "sha256:72dd37233799e619666c9f639a9da83c34013a73e8bbc79a7a6348d93c61fab8"},
@@ -1019,6 +1072,10 @@ livereload = [
     {file = "livereload-2.6.1-py2.py3-none-any.whl", hash = "sha256:78d55f2c268a8823ba499305dcac64e28ddeb9a92571e12d543cd304faf5817b"},
     {file = "livereload-2.6.1.tar.gz", hash = "sha256:89254f78d7529d7ea0a3417d224c34287ebfe266b05e67e51facaf82c27f0f66"},
 ]
+lunr = [
+    {file = "lunr-0.5.6-py2.py3-none-any.whl", hash = "sha256:1208622930c915a07e6f8e8640474357826bad48534c0f57969b6fca9bffc88e"},
+    {file = "lunr-0.5.6.tar.gz", hash = "sha256:7be69d7186f65784a4f2adf81e5c58efd6a9921aa95966babcb1f2f2ada75c20"},
+]
 lxml = [
     {file = "lxml-4.5.0-cp27-cp27m-macosx_10_9_x86_64.whl", hash = "sha256:0701f7965903a1c3f6f09328c1278ac0eee8f56f244e66af79cb224b7ef3801c"},
     {file = "lxml-4.5.0-cp27-cp27m-manylinux1_i686.whl", hash = "sha256:06d4e0bbb1d62e38ae6118406d7cdb4693a3fa34ee3762238bcb96c9e36a93cd"},
@@ -1083,6 +1140,11 @@ markupsafe = [
     {file = "MarkupSafe-1.1.1-cp37-cp37m-manylinux1_x86_64.whl", hash = "sha256:ba59edeaa2fc6114428f1637ffff42da1e311e29382d81b339c1817d37ec93c6"},
     {file = "MarkupSafe-1.1.1-cp37-cp37m-win32.whl", hash = "sha256:b00c1de48212e4cc9603895652c5c410df699856a2853135b3967591e4beebc2"},
     {file = "MarkupSafe-1.1.1-cp37-cp37m-win_amd64.whl", hash = "sha256:9bf40443012702a1d2070043cb6291650a0841ece432556f784f004937f0f32c"},
+    {file = "MarkupSafe-1.1.1-cp38-cp38-macosx_10_9_x86_64.whl", hash = "sha256:6788b695d50a51edb699cb55e35487e430fa21f1ed838122d722e0ff0ac5ba15"},
+    {file = "MarkupSafe-1.1.1-cp38-cp38-manylinux1_i686.whl", hash = "sha256:cdb132fc825c38e1aeec2c8aa9338310d29d337bebbd7baa06889d09a60a1fa2"},
+    {file = "MarkupSafe-1.1.1-cp38-cp38-manylinux1_x86_64.whl", hash = "sha256:13d3144e1e340870b25e7b10b98d779608c02016d5184cfb9927a9f10c689f42"},
+    {file = "MarkupSafe-1.1.1-cp38-cp38-win32.whl", hash = "sha256:596510de112c685489095da617b5bcbbac7dd6384aeebeda4df6025d0256a81b"},
+    {file = "MarkupSafe-1.1.1-cp38-cp38-win_amd64.whl", hash = "sha256:e8313f01ba26fbbe36c7be1966a7b7424942f670f38e666995b88d012765b9be"},
     {file = "MarkupSafe-1.1.1.tar.gz", hash = "sha256:29872e92839765e546828bb7754a68c418d927cd064fd4708fab9fe9c8bb116b"},
 ]
 mccabe = [
@@ -1093,8 +1155,8 @@ mkautodoc = [
     {file = "mkautodoc-0.1.0.tar.gz", hash = "sha256:7c2595f40276b356e576ce7e343338f8b4fa1e02ea904edf33fadf82b68ca67c"},
 ]
 mkdocs = [
-    {file = "mkdocs-1.0.4-py2.py3-none-any.whl", hash = "sha256:8cc8b38325456b9e942c981a209eaeb1e9f3f77b493ad755bfef889b9c8d356a"},
-    {file = "mkdocs-1.0.4.tar.gz", hash = "sha256:17d34329aad75d5de604b9ed4e31df3a4d235afefdc46ce7b1964fddb2e1e939"},
+    {file = "mkdocs-1.1-py2.py3-none-any.whl", hash = "sha256:1e385a70aea8a9dedb731aea4fd5f3704b2074801c4f96f06b2920999babda8a"},
+    {file = "mkdocs-1.1.tar.gz", hash = "sha256:9243291392f59e20b655e4e46210233453faf97787c2cf72176510e868143174"},
 ]
 mkdocs-material = [
     {file = "mkdocs-material-4.6.3.tar.gz", hash = "sha256:1d486635b03f5a2ec87325842f7b10c7ae7daa0eef76b185572eece6a6ea212c"},
@@ -1124,32 +1186,36 @@ multidict = [
     {file = "multidict-4.7.5.tar.gz", hash = "sha256:aee283c49601fa4c13adc64c09c978838a7e812f85377ae130a24d7198c0331e"},
 ]
 mypy = [
-    {file = "mypy-0.761-cp35-cp35m-macosx_10_6_x86_64.whl", hash = "sha256:7f672d02fffcbace4db2b05369142e0506cdcde20cea0e07c7c2171c4fd11dd6"},
-    {file = "mypy-0.761-cp35-cp35m-manylinux1_x86_64.whl", hash = "sha256:87c556fb85d709dacd4b4cb6167eecc5bbb4f0a9864b69136a0d4640fdc76a36"},
-    {file = "mypy-0.761-cp35-cp35m-win_amd64.whl", hash = "sha256:c6d27bd20c3ba60d5b02f20bd28e20091d6286a699174dfad515636cb09b5a72"},
-    {file = "mypy-0.761-cp36-cp36m-macosx_10_6_x86_64.whl", hash = "sha256:4b9365ade157794cef9685791032521233729cb00ce76b0ddc78749abea463d2"},
-    {file = "mypy-0.761-cp36-cp36m-manylinux1_x86_64.whl", hash = "sha256:634aef60b4ff0f650d3e59d4374626ca6153fcaff96ec075b215b568e6ee3cb0"},
-    {file = "mypy-0.761-cp36-cp36m-win_amd64.whl", hash = "sha256:53ea810ae3f83f9c9b452582261ea859828a9ed666f2e1ca840300b69322c474"},
-    {file = "mypy-0.761-cp37-cp37m-macosx_10_6_x86_64.whl", hash = "sha256:0a9a45157e532da06fe56adcfef8a74629566b607fa2c1ac0122d1ff995c748a"},
-    {file = "mypy-0.761-cp37-cp37m-manylinux1_x86_64.whl", hash = "sha256:7eadc91af8270455e0d73565b8964da1642fe226665dd5c9560067cd64d56749"},
-    {file = "mypy-0.761-cp37-cp37m-win_amd64.whl", hash = "sha256:e2bb577d10d09a2d8822a042a23b8d62bc3b269667c9eb8e60a6edfa000211b1"},
-    {file = "mypy-0.761-cp38-cp38-macosx_10_9_x86_64.whl", hash = "sha256:2c35cae79ceb20d47facfad51f952df16c2ae9f45db6cb38405a3da1cf8fc0a7"},
-    {file = "mypy-0.761-cp38-cp38-manylinux1_x86_64.whl", hash = "sha256:f97a605d7c8bc2c6d1172c2f0d5a65b24142e11a58de689046e62c2d632ca8c1"},
-    {file = "mypy-0.761-cp38-cp38-win_amd64.whl", hash = "sha256:a6bd44efee4dc8c3324c13785a9dc3519b3ee3a92cada42d2b57762b7053b49b"},
-    {file = "mypy-0.761-py3-none-any.whl", hash = "sha256:7e396ce53cacd5596ff6d191b47ab0ea18f8e0ec04e15d69728d530e86d4c217"},
-    {file = "mypy-0.761.tar.gz", hash = "sha256:85baab8d74ec601e86134afe2bcccd87820f79d2f8d5798c889507d1088287bf"},
+    {file = "mypy-0.770-cp35-cp35m-macosx_10_6_x86_64.whl", hash = "sha256:a34b577cdf6313bf24755f7a0e3f3c326d5c1f4fe7422d1d06498eb25ad0c600"},
+    {file = "mypy-0.770-cp35-cp35m-manylinux1_x86_64.whl", hash = "sha256:86c857510a9b7c3104cf4cde1568f4921762c8f9842e987bc03ed4f160925754"},
+    {file = "mypy-0.770-cp35-cp35m-win_amd64.whl", hash = "sha256:a8ffcd53cb5dfc131850851cc09f1c44689c2812d0beb954d8138d4f5fc17f65"},
+    {file = "mypy-0.770-cp36-cp36m-macosx_10_6_x86_64.whl", hash = "sha256:7687f6455ec3ed7649d1ae574136835a4272b65b3ddcf01ab8704ac65616c5ce"},
+    {file = "mypy-0.770-cp36-cp36m-manylinux1_x86_64.whl", hash = "sha256:3beff56b453b6ef94ecb2996bea101a08f1f8a9771d3cbf4988a61e4d9973761"},
+    {file = "mypy-0.770-cp36-cp36m-win_amd64.whl", hash = "sha256:15b948e1302682e3682f11f50208b726a246ab4e6c1b39f9264a8796bb416aa2"},
+    {file = "mypy-0.770-cp37-cp37m-macosx_10_6_x86_64.whl", hash = "sha256:b90928f2d9eb2f33162405f32dde9f6dcead63a0971ca8a1b50eb4ca3e35ceb8"},
+    {file = "mypy-0.770-cp37-cp37m-manylinux1_x86_64.whl", hash = "sha256:c56ffe22faa2e51054c5f7a3bc70a370939c2ed4de308c690e7949230c995913"},
+    {file = "mypy-0.770-cp37-cp37m-win_amd64.whl", hash = "sha256:8dfb69fbf9f3aeed18afffb15e319ca7f8da9642336348ddd6cab2713ddcf8f9"},
+    {file = "mypy-0.770-cp38-cp38-macosx_10_9_x86_64.whl", hash = "sha256:219a3116ecd015f8dca7b5d2c366c973509dfb9a8fc97ef044a36e3da66144a1"},
+    {file = "mypy-0.770-cp38-cp38-manylinux1_x86_64.whl", hash = "sha256:7ec45a70d40ede1ec7ad7f95b3c94c9cf4c186a32f6bacb1795b60abd2f9ef27"},
+    {file = "mypy-0.770-cp38-cp38-win_amd64.whl", hash = "sha256:f91c7ae919bbc3f96cd5e5b2e786b2b108343d1d7972ea130f7de27fdd547cf3"},
+    {file = "mypy-0.770-py3-none-any.whl", hash = "sha256:3b1fc683fb204c6b4403a1ef23f0b1fac8e4477091585e0c8c54cbdf7d7bb164"},
+    {file = "mypy-0.770.tar.gz", hash = "sha256:8a627507ef9b307b46a1fea9513d5c98680ba09591253082b4c48697ba05a4ae"},
 ]
 mypy-extensions = [
     {file = "mypy_extensions-0.4.3-py2.py3-none-any.whl", hash = "sha256:090fedd75945a69ae91ce1303b5824f428daf5a028d2f6ab8a299250a846f15d"},
     {file = "mypy_extensions-0.4.3.tar.gz", hash = "sha256:2d82818f5bb3e369420cb3c4060a7970edba416647068eb4c5343488a6c604a8"},
 ]
+nltk = [
+    {file = "nltk-3.4.5.win32.exe", hash = "sha256:a08bdb4b8a1c13de16743068d9eb61c8c71c2e5d642e8e08205c528035843f82"},
+    {file = "nltk-3.4.5.zip", hash = "sha256:bed45551259aa2101381bbdd5df37d44ca2669c5c3dad72439fa459b29137d94"},
+]
 packaging = [
-    {file = "packaging-20.1-py2.py3-none-any.whl", hash = "sha256:170748228214b70b672c581a3dd610ee51f733018650740e98c7df862a583f73"},
-    {file = "packaging-20.1.tar.gz", hash = "sha256:e665345f9eef0c621aa0bf2f8d78cf6d21904eef16a93f020240b704a57f1334"},
+    {file = "packaging-20.3-py2.py3-none-any.whl", hash = "sha256:82f77b9bee21c1bafbf35a84905d604d5d1223801d639cf3ed140bd651c08752"},
+    {file = "packaging-20.3.tar.gz", hash = "sha256:3c292b474fda1671ec57d46d739d072bfd495a4f51ad01a055121d81e952b7a3"},
 ]
 parso = [
-    {file = "parso-0.6.1-py2.py3-none-any.whl", hash = "sha256:951af01f61e6dccd04159042a0706a31ad437864ec6e25d0d7a96a9fbb9b0095"},
-    {file = "parso-0.6.1.tar.gz", hash = "sha256:56b2105a80e9c4df49de85e125feb6be69f49920e121406f15e7acde6c9dfc57"},
+    {file = "parso-0.6.2-py2.py3-none-any.whl", hash = "sha256:8515fc12cfca6ee3aa59138741fc5624d62340c97e401c74875769948d4f2995"},
+    {file = "parso-0.6.2.tar.gz", hash = "sha256:0c5659e0c6eba20636f99a04f469798dca8da279645ce5c387315b2c23912157"},
 ]
 pathspec = [
     {file = "pathspec-0.7.0-py2.py3-none-any.whl", hash = "sha256:163b0632d4e31cef212976cf57b43d9fd6b0bac6e67c26015d611a647d5e7424"},
@@ -1168,8 +1234,8 @@ pluggy = [
     {file = "pluggy-0.13.1.tar.gz", hash = "sha256:15b2acde666561e1298d71b523007ed7364de07029219b604cf808bfa1c765b0"},
 ]
 prompt-toolkit = [
-    {file = "prompt_toolkit-3.0.3-py3-none-any.whl", hash = "sha256:c93e53af97f630f12f5f62a3274e79527936ed466f038953dfa379d4941f651a"},
-    {file = "prompt_toolkit-3.0.3.tar.gz", hash = "sha256:a402e9bf468b63314e37460b68ba68243d55b2f8c4d0192f85a019af3945050e"},
+    {file = "prompt_toolkit-3.0.4-py3-none-any.whl", hash = "sha256:859e1b205b6cf6a51fa57fa34202e45365cf58f8338f0ee9f4e84a4165b37d5b"},
+    {file = "prompt_toolkit-3.0.4.tar.gz", hash = "sha256:ebe6b1b08c888b84c50d7f93dee21a09af39860144ff6130aadbd61ae8d29783"},
 ]
 ptyprocess = [
     {file = "ptyprocess-0.6.0-py2.py3-none-any.whl", hash = "sha256:d7cc528d76e76342423ca640335bd3633420dc1366f258cb31d05e865ef5ca1f"},
@@ -1204,8 +1270,8 @@ pyflakes = [
     {file = "pyflakes-2.1.1.tar.gz", hash = "sha256:d976835886f8c5b31d47970ed689944a0262b5f3afa00a5a7b4dc81e5449f8a2"},
 ]
 pygments = [
-    {file = "Pygments-2.5.2-py2.py3-none-any.whl", hash = "sha256:2a3fe295e54a20164a9df49c75fa58526d3be48e14aceba6d6b1e8ac0bfd6f1b"},
-    {file = "Pygments-2.5.2.tar.gz", hash = "sha256:98c8aa5a9f778fcd1026a17361ddaf7330d1b7c62ae97c3bb0ae73e0b9b6b0fe"},
+    {file = "Pygments-2.6.1-py3-none-any.whl", hash = "sha256:ff7a40b4860b727ab48fad6360eb351cc1b33cbf9b15a0f689ca5353e9463324"},
+    {file = "Pygments-2.6.1.tar.gz", hash = "sha256:647344a061c249a3b74e230c739f434d7ea4d8b1d5f3721bc0f3558049b38f44"},
 ]
 pymdown-extensions = [
     {file = "pymdown-extensions-6.3.tar.gz", hash = "sha256:cb879686a586b22292899771f5e5bc3382808e92aa938f71b550ecdea709419f"},
@@ -1216,8 +1282,8 @@ pyparsing = [
     {file = "pyparsing-2.4.6.tar.gz", hash = "sha256:4c830582a84fb022400b85429791bc551f1f4871c33f23e44f353119e92f969f"},
 ]
 pytest = [
-    {file = "pytest-5.3.5-py3-none-any.whl", hash = "sha256:ff615c761e25eb25df19edddc0b970302d2a9091fbce0e7213298d85fb61fef6"},
-    {file = "pytest-5.3.5.tar.gz", hash = "sha256:0d5fe9189a148acc3c3eb2ac8e1ac0742cb7618c084f3d228baaec0c254b318d"},
+    {file = "pytest-5.4.1-py3-none-any.whl", hash = "sha256:0e5b30f5cb04e887b91b1ee519fa3d89049595f428c1db76e73bd7f17b09b172"},
+    {file = "pytest-5.4.1.tar.gz", hash = "sha256:84dde37075b8805f3d1f392cc47e38a0e59518fb46a431cfdaf7cf1ce805f970"},
 ]
 pytest-asyncio = [
     {file = "pytest-asyncio-0.10.0.tar.gz", hash = "sha256:9fac5100fd716cbecf6ef89233e8590a4ad61d729d1732e0a96b84182df1daaf"},
@@ -1228,8 +1294,8 @@ pytest-cov = [
     {file = "pytest_cov-2.8.1-py2.py3-none-any.whl", hash = "sha256:cdbdef4f870408ebdbfeb44e63e07eb18bb4619fae852f6e760645fa36172626"},
 ]
 pytest-html = [
-    {file = "pytest-html-2.0.1.tar.gz", hash = "sha256:933da7a5e71e5eace9e475441ed88a684f20f6198aa36516cb947ac05edd9921"},
-    {file = "pytest_html-2.0.1-py2.py3-none-any.whl", hash = "sha256:bc40553ca2a1835479c2caf7d48604502cd66d0c5db58ddbca53d74946ee71bd"},
+    {file = "pytest-html-2.1.0.tar.gz", hash = "sha256:8645a8616c8ed7414678e0aeebc3b2fd7d44268773ef5e7289289ad8632c9e91"},
+    {file = "pytest_html-2.1.0-py2.py3-none-any.whl", hash = "sha256:0317a0a589db59c26091ab6068b3edac8d9bc1a8bb9727ade48f806797346956"},
 ]
 pytest-metadata = [
     {file = "pytest-metadata-1.8.0.tar.gz", hash = "sha256:2071a59285de40d7541fde1eb9f1ddea1c9db165882df82781367471238b66ba"},
@@ -1293,13 +1359,15 @@ toml = [
     {file = "toml-0.10.0.tar.gz", hash = "sha256:229f81c57791a41d65e399fc06bf0848bab550a9dfd5ed66df18ce5f05e73d5c"},
 ]
 tornado = [
-    {file = "tornado-6.0.3-cp35-cp35m-win32.whl", hash = "sha256:c9399267c926a4e7c418baa5cbe91c7d1cf362d505a1ef898fde44a07c9dd8a5"},
-    {file = "tornado-6.0.3-cp35-cp35m-win_amd64.whl", hash = "sha256:398e0d35e086ba38a0427c3b37f4337327231942e731edaa6e9fd1865bbd6f60"},
-    {file = "tornado-6.0.3-cp36-cp36m-win32.whl", hash = "sha256:4e73ef678b1a859f0cb29e1d895526a20ea64b5ffd510a2307b5998c7df24281"},
-    {file = "tornado-6.0.3-cp36-cp36m-win_amd64.whl", hash = "sha256:349884248c36801afa19e342a77cc4458caca694b0eda633f5878e458a44cb2c"},
-    {file = "tornado-6.0.3-cp37-cp37m-win32.whl", hash = "sha256:559bce3d31484b665259f50cd94c5c28b961b09315ccd838f284687245f416e5"},
-    {file = "tornado-6.0.3-cp37-cp37m-win_amd64.whl", hash = "sha256:abbe53a39734ef4aba061fca54e30c6b4639d3e1f59653f0da37a0003de148c7"},
-    {file = "tornado-6.0.3.tar.gz", hash = "sha256:c845db36ba616912074c5b1ee897f8e0124df269468f25e4fe21fe72f6edd7a9"},
+    {file = "tornado-6.0.4-cp35-cp35m-win32.whl", hash = "sha256:5217e601700f24e966ddab689f90b7ea4bd91ff3357c3600fa1045e26d68e55d"},
+    {file = "tornado-6.0.4-cp35-cp35m-win_amd64.whl", hash = "sha256:c98232a3ac391f5faea6821b53db8db461157baa788f5d6222a193e9456e1740"},
+    {file = "tornado-6.0.4-cp36-cp36m-win32.whl", hash = "sha256:5f6a07e62e799be5d2330e68d808c8ac41d4a259b9cea61da4101b83cb5dc673"},
+    {file = "tornado-6.0.4-cp36-cp36m-win_amd64.whl", hash = "sha256:c952975c8ba74f546ae6de2e226ab3cc3cc11ae47baf607459a6728585bb542a"},
+    {file = "tornado-6.0.4-cp37-cp37m-win32.whl", hash = "sha256:2c027eb2a393d964b22b5c154d1a23a5f8727db6fda837118a776b29e2b8ebc6"},
+    {file = "tornado-6.0.4-cp37-cp37m-win_amd64.whl", hash = "sha256:5618f72e947533832cbc3dec54e1dffc1747a5cb17d1fd91577ed14fa0dc081b"},
+    {file = "tornado-6.0.4-cp38-cp38-win32.whl", hash = "sha256:22aed82c2ea340c3771e3babc5ef220272f6fd06b5108a53b4976d0d722bcd52"},
+    {file = "tornado-6.0.4-cp38-cp38-win_amd64.whl", hash = "sha256:c58d56003daf1b616336781b26d184023ea4af13ae143d9dda65e31e534940b9"},
+    {file = "tornado-6.0.4.tar.gz", hash = "sha256:0fe2d45ba43b00a41cd73f8be321a44936dc1aba233dee979f17a042b83eb6dc"},
 ]
 traitlets = [
     {file = "traitlets-4.3.3-py2.py3-none-any.whl", hash = "sha256:70b4c6a1d9019d7b4f6846832288f86998aa3b9207c6821f3578a6a6a467fe44"},
@@ -1368,6 +1436,6 @@ yarl = [
     {file = "yarl-1.4.2.tar.gz", hash = "sha256:58cd9c469eced558cd81aa3f484b2924e8897049e06889e8ff2510435b7ef74b"},
 ]
 zipp = [
-    {file = "zipp-3.0.0-py3-none-any.whl", hash = "sha256:12248a63bbdf7548f89cb4c7cda4681e537031eda29c02ea29674bc6854460c2"},
-    {file = "zipp-3.0.0.tar.gz", hash = "sha256:7c0f8e91abc0dc07a5068f315c52cb30c66bfbc581e5b50704c8a2f6ebae794a"},
+    {file = "zipp-3.1.0-py3-none-any.whl", hash = "sha256:aa36550ff0c0b7ef7fa639055d797116ee891440eac1a56f378e2d3179e0320b"},
+    {file = "zipp-3.1.0.tar.gz", hash = "sha256:c599e4d75c98f6798c509911d08a22e6c021d074469042177c8c86fb92eefd96"},
 ]
diff --git a/pyproject.toml b/pyproject.toml
index 119fe577..4ee980ee 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -53,7 +53,7 @@ black = {version = "^19.0", allow-prereleases = true}
 isort = "^4.3"
 flake8 = "^3.7"
 flake8-html = "^0.4.0"
-mypy = "^0.761"
+mypy = "^0.770"
 mkdocs = "^1.0"
 mkdocs-material = "^4.6"
 mkautodoc = "^0.1.0"
diff --git a/tests/test_api/test_client/test_session/test_base_session.py b/tests/test_api/test_client/test_session/test_base_session.py
index cc565a42..422acd3b 100644
--- a/tests/test_api/test_client/test_session/test_base_session.py
+++ b/tests/test_api/test_client/test_session/test_base_session.py
@@ -6,7 +6,6 @@ import pytest
 from aiogram.api.client.session.base import BaseSession, T
 from aiogram.api.client.telegram import PRODUCTION, TelegramAPIServer
 from aiogram.api.methods import GetMe, Response, TelegramMethod
-from aiogram.utils.mixins import DataMixin
 
 try:
     from asynctest import CoroutineMock, patch
@@ -31,7 +30,7 @@ class CustomSession(BaseSession):
         yield b"\f" * 10
 
 
-class TestBaseSession(DataMixin):
+class TestBaseSession():
     def test_init_api(self):
         session = CustomSession()
         assert session.api == PRODUCTION
diff --git a/tests/test_utils/test_mixins.py b/tests/test_utils/test_mixins.py
index 606d6aaa..e7b77727 100644
--- a/tests/test_utils/test_mixins.py
+++ b/tests/test_utils/test_mixins.py
@@ -1,42 +1,11 @@
 import pytest
 
-from aiogram.utils.mixins import ContextInstanceMixin, DataMixin
+from aiogram.utils.mixins import ContextInstanceMixin
 
-
-class DataObject(DataMixin):
+class ContextObject(ContextInstanceMixin['ContextObject']):
     pass
 
 
-class ContextObject(ContextInstanceMixin):
-    pass
-
-
-class TestDataMixin:
-    def test_store_value(self):
-        obj = DataObject()
-        obj["foo"] = 42
-
-        assert "foo" in obj
-        assert obj["foo"] == 42
-        assert len(obj.data) == 1
-
-    def test_remove_value(self):
-        obj = DataObject()
-        obj["foo"] = 42
-        del obj["foo"]
-
-        assert "key" not in obj
-        assert len(obj.data) == 0
-
-    def test_getter(self):
-        obj = DataObject()
-        obj["foo"] = 42
-
-        assert obj.get("foo") == 42
-        assert obj.get("bar") is None
-        assert obj.get("baz", "test") == "test"
-
-
 class TestContextInstanceMixin:
     def test_empty(self):
         obj = ContextObject()