Add asyncio.streams.__all__ (#7275)

Author: AlexWaygood

stdlib/asyncio/streams.pyi

@@ -5,6 +5,65 @@ from typing import Any, AsyncIterator, Awaitable, Callable, Iterable, Optional
 from . import events, protocols, transports
 from .base_events import Server
 
+if sys.platform == "win32":
+    if sys.version_info >= (3, 8):
+        __all__ = ("StreamReader", "StreamWriter", "StreamReaderProtocol", "open_connection", "start_server")
+    elif sys.version_info >= (3, 7):
+        __all__ = (
+            "StreamReader",
+            "StreamWriter",
+            "StreamReaderProtocol",
+            "open_connection",
+            "start_server",
+            "IncompleteReadError",
+            "LimitOverrunError",
+        )
+    else:
+        __all__ = [
+            "StreamReader",
+            "StreamWriter",
+            "StreamReaderProtocol",
+            "open_connection",
+            "start_server",
+            "IncompleteReadError",
+            "LimitOverrunError",
+        ]
+else:
+    if sys.version_info >= (3, 8):
+        __all__ = (
+            "StreamReader",
+            "StreamWriter",
+            "StreamReaderProtocol",
+            "open_connection",
+            "start_server",
+            "open_unix_connection",
+            "start_unix_server",
+        )
+    elif sys.version_info >= (3, 7):
+        __all__ = (
+            "StreamReader",
+            "StreamWriter",
+            "StreamReaderProtocol",
+            "open_connection",
+            "start_server",
+            "IncompleteReadError",
+            "LimitOverrunError",
+            "open_unix_connection",
+            "start_unix_server",
+        )
+    else:
+        __all__ = [
+            "StreamReader",
+            "StreamWriter",
+            "StreamReaderProtocol",
+            "open_connection",
+            "start_server",
+            "IncompleteReadError",
+            "LimitOverrunError",
+            "open_unix_connection",
+            "start_unix_server",
+        ]
+
 _ClientConnectedCallback = Callable[[StreamReader, StreamWriter], Optional[Awaitable[None]]]
 
 if sys.version_info < (3, 8):