code: function getAllOpenFiles() {
          var result = getWorkingSet(ALL_PANES);
          _.forEach(_panes, function (pane) {
              var file = pane.getCurrentlyViewedFile();
              if (file) {
                  result = _.union(result, [file]);
              }
          });
          return result;
      }
docs: Retrieves the list of all open files including temporary views
  @return {array.<File>} the list of all open files in all open panes