remove redundant overloads

asyncstdlib/contextlib.py

@@ -1,4 +1,3 @@
-from __future__ import annotations
 from typing import (
     TypeVar,
     Generic,
@@ -9,7 +8,6 @@
     Any,
     Awaitable,
     Deque,
-    overload,
     AsyncContextManager,
 )
 from functools import wraps
@@ -184,22 +182,10 @@ async def safe_fetch(source):
 
     __slots__ = ("enter_result",)
 
-    @overload
-    def __init__(self: NullContext[None], enter_result: None = ...) -> None: ...
-
-    @overload
-    def __init__(self: NullContext[T], enter_result: T) -> None: ...
-
-    def __init__(self, enter_result: Optional[T] = None):
+    def __init__(self, enter_result: T = None):
         self.enter_result = enter_result
 
-    @overload
-    async def __aenter__(self: NullContext[None]) -> None: ...
-
-    @overload
-    async def __aenter__(self: NullContext[T]) -> T: ...
-
-    async def __aenter__(self) -> Optional[T]:
+    async def __aenter__(self) -> T:
         return self.enter_result
 
     async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> bool:

asyncstdlib/contextlib.pyi

@@ -39,9 +39,6 @@ class nullcontext(AsyncContextManager[T]):
     def __init__(self: nullcontext[None], enter_result: None = ...) -> None: ...
     @overload
     def __init__(self: nullcontext[T], enter_result: T) -> None: ...
-    @overload
-    async def __aenter__(self: nullcontext[None]) -> None: ...
-    @overload
     async def __aenter__(self: nullcontext[T]) -> T: ...
     async def __aexit__(
         self,