code: function close() {
      if (watcher && !closed) {
        if (options.persistent) {
          // Close handle only if watcher was created persistent.
          watcher.close();
        }
        else {
          // Stop handling change events.
          watcher.removeAllListeners();
          // Leave watcher on error events that may come from unclosed handle.
          watcher.on('error', function (err) { });
        }
        closed = true;
      }
    }
docs: Cleanup rebus instance.