B2G/gecko/browser/devtools/shared/Undo.jsm
/**
   * Perform an action, adding it to the undo stack.
   *
   * @param function aDo Called to perform the action.
   * @param function aUndo Called to reverse the action.
   */
Perform an action, adding it to the undo stack.
@param function aDo Called to perform the action.
@param function aUndo Called to reverse the action.
Perform an action adding it to the undo stack . @param function aDo Called to perform the action . @param function aUndo Called to reverse the action .
function Undo_do(aDo, aUndo) {
    this.startBatch();
    this._batch.push({ do: aDo, undo: aUndo });
    this.endBatch();
  }
function Undo_do ( aDo , aUndo ) { this . startBatch ( ) ; this . _batch . push ( { do : aDo , undo : aUndo } ) ; this . endBatch ( ) ; }
Perform an action, adding it to the undo stack.
Perform an action adding it to the undo stack .