### Question:
Second extends RegularTimePeriod implements Serializable { @Override public long getSerialIndex() { long hourIndex = this.day.getSerialIndex() * 24L + this.hour; long minuteIndex = hourIndex * 60L + this.minute; return minuteIndex * 60L + this.second; } Second();  Second(int second, Minute minute);  Second(int second, int minute, int hour,
                  int day, int month, int year);  Second(Date time);  Second(Date time, TimeZone zone, Locale locale); int getSecond(); Minute getMinute(); @Override long getFirstMillisecond(); @Override long getLastMillisecond(); @Override void peg(Calendar calendar); @Override RegularTimePeriod previous(); @Override RegularTimePeriod next(); @Override long getSerialIndex(); @Override long getFirstMillisecond(Calendar calendar); @Override long getLastMillisecond(Calendar calendar); @Override boolean equals(Object obj); @Override int hashCode(); @Override int compareTo(TimePeriod o1); static Second parseSecond(String s); static final int FIRST_SECOND_IN_MINUTE; static final int LAST_SECOND_IN_MINUTE; }### Answer:
@Test public void testGetSerialIndex() { Second s = new Second(1, 1, 1, 1, 1, 2000); assertEquals(3155850061L, s.getSerialIndex()); s = new Second(1, 1, 1, 1, 1, 1900); assertEquals(176461L, s.getSerialIndex()); }