code: public OffsetRange<OffsetType> shiftedCopy(final int shiftAmount) {
      return new OffsetRange<>(startInclusive().shiftedCopy(shiftAmount),
          endInclusive().shiftedCopy(shiftAmount));
    }
docs: Returns a new {@code OffsetRange} of the same type with the start and end points
  shifted by the specified amount.