def AllFieldsFromDescriptor(self, message_descriptor):
    """Gets all direct fields of Message Descriptor to FieldMask."""
    self.Clear()
    for field in message_descriptor.fields:
      self.paths.append(field.name)
Gets all direct fields of Message Descriptor to FieldMask.
deps/protobuf/python/google/protobuf/internal/well_known_types.py