def _isWatched(self, path):
        """
        Helper function that checks if the path is already monitored
        and returns its watchdescriptor if so or None otherwise.

        @param path: The path that should be checked
        @type path: L{FilePath}
        """
        path = path.asBytesMode()
        return self._watchpaths.get(path, None)

        Helper function that checks if the path is already monitored
        and returns its watchdescriptor if so or None otherwise.

        @param path: The path that should be checked
        @type path: L{FilePath}
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/inotify.py