code: public static NDArrayMessage wholeArrayUpdate(INDArray arr) {
          return NDArrayMessage.builder().arr(arr).dimensions(WHOLE_ARRAY_UPDATE).index(WHOLE_ARRAY_INDEX)
                          .sent(getCurrentTimeUtc()).build();
      }
docs: Prepare a whole array update
  which includes the default dimensions
  for indicating updating
  the whole array (a 1 length int array with -1 as its only element)
  -1 representing the dimension
  @param arr
  @return