presto-spi/src/main/java/io/prestosql/spi/type/ArrayType.java/ArrayType/appendTo
class ArrayType:    @Override
    public void appendTo(Block block, int position, BlockBuilder blockBuilder)
    {
        if (block.isNull(position)) {
            blockBuilder.appendNull();
        }
        else {
            block.writePositionTo(position, blockBuilder);
        }
    }