Add write method in NamedTemporaryFileResult

Author: deveshks

src/pip/_internal/utils/filesystem.py

@@ -17,14 +17,20 @@
 from pip._internal.utils.typing import MYPY_CHECK_RUNNING, cast
 
 if MYPY_CHECK_RUNNING:
-    from typing import Any, BinaryIO, Iterator, List, Union
+    import abc
+    from typing import Any, BinaryIO, Iterator, List, Union, AnyStr
 
     class NamedTemporaryFileResult(BinaryIO):
         @property
         def file(self):
             # type: () -> BinaryIO
             pass
 
+        @abc.abstractmethod
+        def write(self, s):
+            # type: (AnyStr) -> int
+            pass
+
 
 def check_path_owner(path):
     # type: (str) -> bool