presto-main/src/main/java/io/prestosql/operator/aggregation/IntervalYearToMonthSumAggregation.java/IntervalYearToMonthSumAggregation/sum
class IntervalYearToMonthSumAggregation:    @InputFunction
    public static void sum(NullableLongState state, @SqlType(INTERVAL_YEAR_TO_MONTH) long value)
    {
        state.setNull(false);
        state.setLong(BigintOperators.add(state.getLong(), value));
    }