presto-spi/src/main/java/io/prestosql/spi/block/ShortArrayBlock.java/ShortArrayBlock/getRegion
class ShortArrayBlock:    @Override
    public Block getRegion(int positionOffset, int length)
    {
        checkValidRegion(getPositionCount(), positionOffset, length);

        return new ShortArrayBlock(positionOffset + arrayOffset, length, valueIsNull, values);
    }