code: public static <T> ApolloPrefetchCallback wrap(@NotNull ApolloPrefetch.Callback callback, @NotNull Handler handler) {
      return new ApolloPrefetchCallback(callback, handler);
    }
docs: Wraps {@code callback} to be be operated on specified {@code handler}
  
  @param callback original callback to delegates calls
  @param handler  the callback will be run on the thread to which this handler is attached