Added __class_getitem__ (#4695)

Resolves #4682

Co-authored-by: hauntsaninja <>

third_party/2/concurrent/futures/_base.pyi

@@ -5,6 +5,9 @@ from logging import Logger
 from types import TracebackType
 from typing import Any, Callable, Container, Generic, Iterable, Iterator, List, Optional, Protocol, Set, Tuple, TypeVar
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 FIRST_COMPLETED: str
 FIRST_EXCEPTION: str
 ALL_COMPLETED: str
@@ -54,6 +57,8 @@ class Future(Generic[_T]):
         def exception_info(self, timeout: Optional[float] = ...) -> Tuple[Any, Optional[TracebackType]]: ...
         def set_exception(self, exception: Any) -> None: ...
         def set_exception_info(self, exception: Any, traceback: Optional[TracebackType]) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...
 
 class Executor:
     if sys.version_info >= (3, 9):

third_party/2/concurrent/futures/thread.pyi

@@ -7,6 +7,9 @@ if sys.version_info >= (3, 7):
     from ._base import BrokenExecutor
     class BrokenThreadPool(BrokenExecutor): ...
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _S = TypeVar("_S")
 
 class ThreadPoolExecutor(Executor):
@@ -30,3 +33,5 @@ class _WorkItem(Generic[_S]):
     kwargs: Mapping[str, Any]
     def __init__(self, future: Future[_S], fn: Callable[..., _S], args: Iterable[Any], kwargs: Mapping[str, Any]) -> None: ...
     def run(self) -> None: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, item: Any) -> GenericAlias: ...

third_party/2/pathlib2.pyi

@@ -6,6 +6,9 @@ from types import TracebackType
 from typing import IO, Any, BinaryIO, Generator, List, Optional, Sequence, Text, TextIO, Tuple, Type, TypeVar, Union, overload
 from typing_extensions import Literal
 
+if sys.version_info >= (3, 9):
+    from types import GenericAlias
+
 _P = TypeVar("_P", bound=PurePath)
 
 if sys.version_info >= (3, 6):
@@ -52,6 +55,8 @@ class PurePath(_PurePathBase):
     def parents(self: _P) -> Sequence[_P]: ...
     @property
     def parent(self: _P) -> _P: ...
+    if sys.version_info >= (3, 9):
+        def __class_getitem__(cls, type: Any) -> GenericAlias: ...
 
 class PurePosixPath(PurePath): ...
 class PureWindowsPath(PurePath): ...