code: function onMessage(data) {
      if (data.type == "utf8") {
          message = JSON.parse(data.utf8Data);
          switch (message.command) {
              case "setJoints":
                  console.log("Client has request to add joints: " + message.data);
                  nuimotion.jointsTracking = message.data;
                  break;
  
              case "addListener":
                  console.log("Client has request to add events: " + message.data);
                  if (!nuimotion._eventCallbackDict[message.data]) {
                      nuimotion.addListener(message.data, onEvent);
                  }
                  break;
  
              case "addGesture":
                  console.log("Client has request to add gestures: " + message.data);
                  if (!nuimotion._gestureCallbackDict[message.data]) {
                      nuimotion.addGesture(message.data, onEvent);
                  }
                  break;
          }
      }
  }
docs: on message recieved from client
  @param data