code: function showOpenDialog(allowMultipleSelection, chooseDirectories, title, initialPath, fileTypes, callback) {
          appshell.fs.showOpenDialog(allowMultipleSelection, chooseDirectories, title, initialPath, fileTypes, _wrap(callback));
      }
docs: Display an open-files dialog to the user and call back asynchronously with
  either a FileSystmError string or an array of path strings, which indicate
  the entry or entries selected.
  
  @param {boolean} allowMultipleSelection
  @param {boolean} chooseDirectories
  @param {string} title
  @param {string} initialPath
  @param {Array.<string>=} fileTypes
  @param {function(?string, Array.<string>=)} callback