presto-iceberg/src/main/java/io/prestosql/plugin/iceberg/PartitionTransforms.java/PartitionTransforms/bucketBigint
class PartitionTransforms:    private static Block bucketBigint(Block block, int count)
    {
        return bucketBlock(block, count, position -> bucketHash(BIGINT.getLong(block, position)));
    }