presto-spi/src/main/java/io/prestosql/spi/type/DoubleType.java/DoubleType/appendTo
class DoubleType:    @Override
    public void appendTo(Block block, int position, BlockBuilder blockBuilder)
    {
        if (block.isNull(position)) {
            blockBuilder.appendNull();
        }
        else {
            blockBuilder.writeLong(block.getLong(position, 0)).closeEntry();
        }
    }