presto-main/src/main/java/io/prestosql/type/IntegerOperators.java/IntegerOperators/hashCode
class IntegerOperators:    @ScalarOperator(HASH_CODE)
    @SqlType(StandardTypes.BIGINT)
    public static long hashCode(@SqlType(StandardTypes.INTEGER) long value)
    {
        return AbstractIntType.hash((int) value);
    }