Merge branch 'maint/5.0' into cpython

Author: jaraco

Lib/importlib/_common.py

@@ -7,14 +7,15 @@
 import importlib
 
 from typing import Union, Any, Optional
-from .abc import ResourceReader
+from .abc import ResourceReader, Traversable
 
 from ._adapters import wrap_spec
 
 Package = Union[types.ModuleType, str]
 
 
 def files(package):
+    # type: (Package) -> Traversable
     """
     Get a Traversable resource from a package
     """