presto-spi/src/main/java/io/prestosql/spi/type/ArrayType.java/ArrayType/hash
class ArrayType:    @Override
    public long hash(Block block, int position)
    {
        Block array = getObject(block, position);
        long hash = 0;
        for (int i = 0; i < array.getPositionCount(); i++) {
            hash = 31 * hash + hashPosition(elementType, array, i);
        }
        return hash;
    }