code: func (v *View) DataAndLastIndex() (interface{}, uint64) {
  	v.dataLock.RLock()
  	defer v.dataLock.RUnlock()
  	return v.data, v.lastIndex
  }
docs: // DataAndLastIndex returns the most-recently-received data from Consul for
  // this view, along with the last index. This is atomic so you will get the
  // index that goes with the data you are fetching.