### Question:
Hour extends RegularTimePeriod implements Serializable { @Override public long getFirstMillisecond() { return this.firstMillisecond; } Hour();  Hour(int hour, Day day);  Hour(int hour, int day, int month, int year);  Hour(Date time);  Hour(Date time, TimeZone zone, Locale locale); int getHour(); Day getDay(); int getYear(); int getMonth(); int getDayOfMonth(); @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 String toString(); @Override int hashCode(); @Override int compareTo(TimePeriod o1); static Hour parseHour(String s); static final int FIRST_HOUR_IN_DAY; static final int LAST_HOUR_IN_DAY; }### Answer:
@Test public void testGetFirstMillisecond() { Locale saved = Locale.getDefault(); Locale.setDefault(Locale.UK); TimeZone savedZone = TimeZone.getDefault(); TimeZone.setDefault(TimeZone.getTimeZone("Europe/London")); Hour h = new Hour(15, 1, 4, 2006); assertEquals(1143900000000L, h.getFirstMillisecond()); Locale.setDefault(saved); TimeZone.setDefault(savedZone); }
@Test public void testGetFirstMillisecondWithTimeZone() { Hour h = new Hour(15, 1, 4, 1950); TimeZone zone = TimeZone.getTimeZone("America/Los_Angeles"); Calendar c = new GregorianCalendar(zone); assertEquals(-623293200000L, h.getFirstMillisecond(c)); try { h.getFirstMillisecond(null); fail("NullPointerException should have been thrown on null parameter"); } catch (NullPointerException e) { } }
@Test public void testGetFirstMillisecondWithCalendar() { Hour h = new Hour(2, 15, 4, 2000); GregorianCalendar calendar = new GregorianCalendar(Locale.GERMANY); calendar.setTimeZone(TimeZone.getTimeZone("Europe/Frankfurt")); assertEquals(955764000000L, h.getFirstMillisecond(calendar)); try { h.getFirstMillisecond(null); fail("NullPointerException should have been thrown on null parameter"); } catch (NullPointerException e) { } }