### Question:
ThreeSixtyDayChronology extends FixedYearLengthChronology { @Override public DateTimeField monthOfYear() { return this.monthOfYear; } private  ThreeSixtyDayChronology(); static ThreeSixtyDayChronology getInstanceUTC(); @Override DurationField months(); @Override DateTimeField dayOfMonth(); @Override DateTimeField monthOfYear(); @Override String toString();  }### Answer:
@Test public void testMonthArithmetic2() { long millis = sample.getMillis(); assertEquals(millis + 4 * MONTH, sample.monthOfYear().addToCopy(4).getMillis()); assertEquals(millis - 4 * MONTH, sample.monthOfYear().addToCopy(-4).getMillis()); }