@Test
public void testMinusMonths()
{

    DateTimeUnit dateTimeUnit = new DateTimeUnit( 1382, 1, 20 );
    DateTimeUnit testDateTimeUnit = calendar.minusMonths( dateTimeUnit, 1 );
    assertEquals( 1381, testDateTimeUnit.getYear() );
    assertEquals( 12, testDateTimeUnit.getMonth() );
    assertEquals( 20, testDateTimeUnit.getDay() );
}