code: function getLatencyAndWait() {
        var result = null;
  
        if (isDestroyed) {
          return Promise.resolve(result);
        }
  
        return getLatency(slave)
            .then(function (latency) { result = latency })  // store the retrieved latency
            .catch(function (err)    { console.log(err) })  // just log failed requests
            .then(function () { return util.wait(DELAY) })  // wait 1 sec
            .then(function () { return result});            // return the retrieved latency
      }
docs: retrieve latency, then wait 1 sec