def handles(self, src, path):
if not pathtools.patterns.match_path(path, self.patterns,<EOL>self.ignore_patterns):<EOL><INDENT>return None<EOL><DEDENT>return self._outputs(src, path)<EOL>
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..