presto-main/src/main/java/io/prestosql/type/IntervalYearMonthOperators.java/IntervalYearMonthOperators/negate
class IntervalYearMonthOperators:    @ScalarOperator(NEGATION)
    @SqlType(StandardTypes.INTERVAL_YEAR_TO_MONTH)
    public static long negate(@SqlType(StandardTypes.INTERVAL_YEAR_TO_MONTH) long value)
    {
        return -value;
    }