code: def files(self):
          
          directory = self.get_directory()
          prefix = len(directory) + (0 if is_root(directory) else 1)
  
          include = None
          exclude = None
          for root, dirs, files in self.walk_func(directory, followlinks=self.symlinks):
              # Remove the constant part of the path inluding the first path sep
              rel_dir_name = root[prefix:]
              matched, include, exclude = self._receive(
                  directory, rel_dir_name, dirs, files, include, exclude)
              for file_name in matched:
                  yield rel_dir_name, file_name
docs: A generator function for iterating over the individual files of
          the FileSet.
  
          The generator yields a tuple of ``(rel_dir_name, file_name)``:
  
          1. *rel_dir_name*: The path relative to the starting directory
          2. *file_name*: The unqualified file name