code: def handles(self, src, path):
          
          if not pathtools.patterns.match_path(path, self.patterns,
                                               self.ignore_patterns):
              return None
  
          return self._outputs(src, path)
docs: Must return a list of files that this handler will produce after
          successfully processing `path`. If the current handler does not operate
          on `path`, None should be returned. If instead `path` should not
          produce output by itself (but should be compiled nonetheless), then an
          empty list should be returned. This function will be called every time
          the file identified by `path` changes (only the modification time is
          taken into account; `src` is provided for convenience; it allows direct
          access to the file's contents..