How to use

methodCall

function

in

Client

call(method, args) {
    return new Promise((resolve, reject) => {
      this.client.methodCall(method, [...args], (err, data) => {
        if (err) return reject(this.handleError(err))
        resolve(data)
      })
    })
  }

requestTopic(callerId, topic, protocols) {
  let data = [callerId, topic, protocols];
  return new Promise((resolve, reject) => {
   this._xmlrpcClient.methodCall('requestTopic', data, (err, resp) => {
    if (err || resp[0] !== 1) {
     reject(err, resp);
    }
    else {
   resolve(resp);
    }
   });
  });
 }