code: def get_modified_time(self) -> Optional[datetime.datetime]:
          
          stat_result = self._stat()
          # NOTE: Historically, this used stat_result[stat.ST_MTIME],
          # which truncates the fractional portion of the timestamp. It
          # was changed from that form to stat_result.st_mtime to
          # satisfy mypy (which disallows the bracket operator), but the
          # latter form returns a float instead of an int. For
          # consistency with the past (and because we have a unit test
          # that relies on this), we truncate the float here, although
          # I'm not sure that's the right thing to do.
          modified = datetime.datetime.utcfromtimestamp(int(stat_result.st_mtime))
          return modified
docs: Returns the time that ``self.absolute_path`` was last modified.
  
          May be overridden in subclasses.  Should return a `~datetime.datetime`
          object or None.
  
          .. versionadded:: 3.1