code: @NotNull
      public static LongStream rangeClosed(final long startInclusive, final long endInclusive) {
          if (startInclusive > endInclusive) {
              return empty();
          } else if (startInclusive == endInclusive) {
              return of(startInclusive);
          } else return new LongStream(new LongRangeClosed(startInclusive, endInclusive));
      }
docs: Returns a sequential ordered {@code LongStream} from {@code startInclusive}
  (inclusive) to {@code endInclusive} (inclusive) by an incremental step of
  {@code 1}.
  
  @param startInclusive the (inclusive) initial value
  @param endInclusive the inclusive upper bound
  @return a sequential {@code LongStream} for the range of {@code long}
  elements