code: def modified(self, base: pathlib.PurePath = pathlib.PurePath()) \
              -> Iterator[str]:
          
          # N.B. this method will only ever return files, as directories cannot
          # be "modified"
          if self.is_modified:
              yield str(base / self.right.name)
docs: Find the paths of modified files. There is no option to include
          intermediate directories, as all files and directories exist in both
          the left and right trees.
  
          :param base: The base directory to recursively append to the right
                       entity.
          :return: An iterable of paths of modified files.