code: function watchPath(path, ignored, callback) {
          if (_isRunningOnWindowsXP) {
              callback(FileSystemError.NOT_SUPPORTED);
              return;
          }
          appshell.fs.isNetworkDrive(path, function (err, isNetworkDrive) {
              if (err || isNetworkDrive) {
                  if (isNetworkDrive) {
                      callback(FileSystemError.NETWORK_DRIVE_NOT_SUPPORTED);
                  } else {
                      callback(FileSystemError.UNKNOWN);
                  }
                  return;
              }
              _nodeDomain.exec("watchPath", path, ignored)
                  .then(callback, callback);
          });
      }
docs: Start providing change notifications for the file or directory at the
  given path, calling back asynchronously with a possibly null FileSystemError
  string when the initialization is complete. Notifications are provided
  using the changeCallback function provided by the initWatchers method.
  Note that change notifications are only provided recursively for directories
  when the recursiveWatch property of this module is true.
  
  @param {string} path
  @param {Array<string>} ignored
  @param {function(?string)=} callback