@ConstantFunction(name = "minutes_sub", argTypes = {DATETIME, INT}, returnType = DATETIME, isMonotonic = true)
    public static ConstantOperator minutesSub(ConstantOperator date, ConstantOperator minute) {
        return ConstantOperator.createDatetimeOrNull(date.getDatetime().minusMinutes(minute.getInt()));
    }
@Test
    public void minutesSub() {
        assertEquals("2015-03-23T09:13:55",
                ScalarOperatorFunctions.minutesSub(O_DT_20150323_092355, O_INT_10).getDatetime().toString());
    }