Upgrade black to 21.4b0 and reformat (#5250)

This introduces newlines before decorators.

requirements-tests-py3.txt

@@ -2,7 +2,7 @@
 # typeshed is released on PyPI.
 git+https://github.com/python/mypy.git@master
 typed-ast>=1.0.4
-black==20.8b1
+black==21.4b0
 flake8==3.8.4
 flake8-bugbear==20.1.4
 flake8-pyi==20.10.0

stdlib/@python2/_functools.pyi

@@ -2,6 +2,7 @@ from typing import Any, Callable, Dict, Iterable, Optional, Tuple, TypeVar, over
 
 _T = TypeVar("_T")
 _S = TypeVar("_S")
+
 @overload
 def reduce(function: Callable[[_T, _T], _T], sequence: Iterable[_T]) -> _T: ...
 @overload

stdlib/@python2/functools.pyi

@@ -5,6 +5,7 @@ _AnyCallable = Callable[..., Any]
 
 _T = TypeVar("_T")
 _S = TypeVar("_S")
+
 @overload
 def reduce(function: Callable[[_T, _T], _T], sequence: Iterable[_T]) -> _T: ...
 @overload

stdlib/@python2/itertools.pyi

@@ -38,6 +38,7 @@ _T3 = TypeVar("_T3")
 _T4 = TypeVar("_T4")
 _T5 = TypeVar("_T5")
 _T6 = TypeVar("_T6")
+
 @overload
 def imap(func: Callable[[_T1], _S], iter1: Iterable[_T1]) -> Iterator[_S]: ...
 @overload

stdlib/codecs.pyi

@@ -69,6 +69,7 @@ _BytesToBytesEncodingT = Literal[
     "zlib",
     "zlib_codec",
 ]
+
 @overload
 def encode(obj: bytes, encoding: _BytesToBytesEncodingT, errors: str = ...) -> bytes: ...
 @overload

stdlib/dataclasses.pyi

@@ -9,6 +9,7 @@ _T = TypeVar("_T")
 class _MISSING_TYPE: ...
 
 MISSING: _MISSING_TYPE
+
 @overload
 def asdict(obj: Any) -> Dict[str, Any]: ...
 @overload

stdlib/fcntl.pyi

@@ -80,6 +80,7 @@ LOCK_RW: int
 LOCK_SH: int
 LOCK_UN: int
 LOCK_WRITE: int
+
 @overload
 def fcntl(__fd: FileDescriptorLike, __cmd: int, __arg: int = ...) -> int: ...
 @overload
@@ -87,6 +88,7 @@ def fcntl(__fd: FileDescriptorLike, __cmd: int, __arg: bytes) -> bytes: ...
 
 _ReadOnlyBuffer = bytes
 _WritableBuffer = Union[bytearray, memoryview, array[Any]]
+
 @overload
 def ioctl(__fd: FileDescriptorLike, __request: int, __arg: int = ..., __mutate_flag: bool = ...) -> int: ...
 @overload

stdlib/functools.pyi

@@ -25,6 +25,7 @@ _AnyCallable = Callable[..., Any]
 
 _T = TypeVar("_T")
 _S = TypeVar("_S")
+
 @overload
 def reduce(function: Callable[[_T, _S], _T], sequence: Iterable[_S], initial: _T) -> _T: ...
 @overload

stdlib/gettext.pyi

@@ -29,6 +29,7 @@ class GNUTranslations(NullTranslations):
 def find(domain: str, localedir: Optional[StrPath] = ..., languages: Optional[Iterable[str]] = ..., all: bool = ...) -> Any: ...
 
 _T = TypeVar("_T")
+
 @overload
 def translation(
     domain: str,

stdlib/http/cookies.pyi

@@ -3,6 +3,7 @@ from typing import Any, Dict, Generic, Iterable, List, Mapping, Optional, Tuple,
 
 _DataType = Union[str, Mapping[str, Union[str, Morsel[Any]]]]
 _T = TypeVar("_T")
+
 @overload
 def _quote(str: None) -> None: ...
 @overload

stdlib/os/__init__.pyi

@@ -433,6 +433,7 @@ if sys.platform != "win32":
     def unsetenv(__name: Union[bytes, str]) -> None: ...
 
 _Opener = Callable[[str, int], int]
+
 @overload
 def fdopen(
     fd: int,

stdlib/posix.pyi

@@ -149,6 +149,7 @@ WUNTRACED: int
 XATTR_CREATE: int
 XATTR_REPLACE: int
 XATTR_SIZE_MAX: int
+
 @overload
 def listdir(path: Optional[str] = ...) -> List[str]: ...
 @overload

stdlib/wsgiref/simple_server.pyi

@@ -33,6 +33,7 @@ class WSGIRequestHandler(BaseHTTPRequestHandler):
 def demo_app(environ: WSGIEnvironment, start_response: StartResponse) -> List[bytes]: ...
 
 _S = TypeVar("_S", bound=WSGIServer)
+
 @overload
 def make_server(host: str, port: int, app: WSGIApplication, *, handler_class: Type[WSGIRequestHandler] = ...) -> WSGIServer: ...
 @overload

stubs/Werkzeug/werkzeug/utils.pyi

@@ -36,6 +36,7 @@ def unescape(s): ...
 # 'redirect' returns a werkzeug Response, unless you give it
 # another Response type to use instead.
 _RC = TypeVar("_RC", bound=Response)
+
 @overload
 def redirect(location: str, code: int = ..., Response: None = ...) -> Response: ...
 @overload

stubs/click/click/termui.pyi

@@ -26,6 +26,7 @@ def echo_via_pager(
 ) -> None: ...
 
 _T = TypeVar("_T")
+
 @overload
 def progressbar(
     iterable: Iterable[_T],

stubs/dataclasses/dataclasses.pyi

@@ -9,6 +9,7 @@ _T = TypeVar("_T")
 class _MISSING_TYPE: ...
 
 MISSING: _MISSING_TYPE
+
 @overload
 def asdict(obj: Any) -> Dict[str, Any]: ...
 @overload

stubs/first/first.pyi

@@ -2,6 +2,7 @@ from typing import Any, Callable, Iterable, Optional, TypeVar, Union, overload
 
 _T = TypeVar("_T")
 _S = TypeVar("_S")
+
 @overload
 def first(iterable: Iterable[_T]) -> Optional[_T]: ...
 @overload

stubs/redis/redis/utils.pyi

@@ -6,6 +6,7 @@ from .client import Pipeline, Redis
 _T = TypeVar("_T")
 
 HIREDIS_AVAILABLE: bool
+
 @overload
 def from_url(url: Text, db: Optional[int] = ..., *, decode_responses: Literal[True], **kwargs: Any) -> Redis[str]: ...
 @overload