code: function(port, host, opts) {
    if (!(this instanceof Connector)) {
      return new Connector(port, host, opts);
    }
  
    EventEmitter.call(this);
    this.port = port;
    this.host = host;
    this.opts = opts || {};
  
    this.adaptor = new Adaptor(this.opts);
  }
docs: Connector that manager low level connection and protocol bewteen server and client.
  Develper can provide their own connector to switch the low level prototol, such as tcp or probuf.