--- /dev/null
+from typing import Optional, Any\r
+from ._base import Future, Executor\r
+import sys\r
+\r
+EXTRA_QUEUED_CALLS = ... # type: Any\r
+\r
+if sys.version_info >= (3,):\r
+ class BrokenProcessPool(RuntimeError): ...\r
+\r
+class ProcessPoolExecutor(Executor):\r
+ def __init__(self, max_workers: Optional[int] = ...) -> None: ...\r