code: function onEvent(event) {
      if (event.eventType == nuimotion.Events.GESTURE) {
          console.log("Gesture: " + event.gestureType + " Hand: " + event.hand + " State: " + event.step);
      } else {
          console.log("Event: " + event.eventType);
      }
  }
docs: on general event (user/device/gesture/etc)
  @param event