undo method

@override Future<ResultCode> undo()

Undo the last operation of the whiteboard.

Returns

• ResultCode.OK Success
• others: Failure

撤销白板上一次操作。

Returns

• ResultCode.OK 成功
• 其他: 失败

Implementation

@override
Future<ResultCode> undo() {
  return _invokeCodeMethod('undo');
}