docs: public static ToDoubleFunction<IntTuple> asFunction(
          final DoubleArrayND array)
      {
          Objects.requireNonNull(array, "The array is null");
          return new ToDoubleFunction<IntTuple>()
          {
              @Override
              public double applyAsDouble(IntTuple s)
              {
                  return array.get(s);
              }
          };
      }