code: function (device, serviceHandle, functionName, errorCallback) {
  			var service = device.serviceList[serviceHandle];
  			if (service == null) {
  				var msg = "Could not find the requested service handle '" + serviceHandle + "'";
  				winble.logger.logError(functionName, msg);
  				errorCallback(msg);
  			}
  			return (service);
  		}
docs: Called internally to look up a previously discovered service by handle. Look up the requested service and complain if we can't find it.