export interface MqttOptions {
  host: string;
  port: number;
  clientId: string;
  username: string;
  password: string;
  useSSL: boolean;

  onConnectionLost: (event: any) => void;
  onMessageArrived: (message: any) => void;
  onMessageDelivered: (event: any) => void;

  /**
   * 是否打印收到的 `websocket` 消息内容
   */
  _logMessage: boolean;
}