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..

def handles(self, src, path):
        """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.."""
        if not pathtools.patterns.match_path(path, self.patterns,
                                             self.ignore_patterns):
            return None

        return self._outputs(src, path)