Add type hints to self.run wrapper

src/pip/_internal/cli/base_command.py

@@ -36,12 +36,14 @@
 
 if MYPY_CHECK_RUNNING:
     from optparse import Values
-    from typing import Any, List, Optional, Tuple
+    from typing import Any, Callable, List, Optional, Tuple
 
     from pip._internal.utils.temp_dir import (
         TempDirectoryTypeRegistry as TempDirRegistry,
     )
 
+    status = int
+
 __all__ = ['Command']
 
 logger = logging.getLogger(__name__)
@@ -189,8 +191,10 @@ def _main(self, args):
             )
 
         def intercepts_unhandled_exc(run_func):
+            # type: (Callable[..., status]) -> Callable[..., status]
             @wraps(run_func)
             def exc_logging_wrapper(*args):
+                # type: (*args) -> status
                 try:
                     status = run_func(*args)
                     assert isinstance(status, int)