### Question:
TimePeriod implements Comparable<TimePeriod> { @Override public int hashCode() { int hash = 5; hash = 29 * hash + Objects.hashCode(this.startTime); hash = 29 * hash + Objects.hashCode(this.endTime); return hash; } TimePeriod(long startTime, long endTime);  TimePeriod(Calendar startTime, Calendar endTime);  TimePeriod(Calendar startTime, long seconds);  TimePeriod(Calendar startTime, int time, TimeUnit sourceUnit);  TimePeriod(int time, TimeUnit sourceUnit); long getDuration(); static long convertToMinutes(TimePeriod duration); static long convertToHours(TimePeriod duration); static long convertToDays(TimePeriod duration); Calendar getStartTime(); long getStartTimeInSeconds(); Calendar getEndTime(); long getEndTimeInSeconds(); @Override boolean equals(Object obj); @Override int hashCode(); @Override int compareTo(TimePeriod other); @Override String toString(); boolean isValid();  }### Answer:
@Test public void testHashCode() { System.out.println("hashCode"); TimePeriod instance = new TimePeriod(time1, time2); int result = instance.hashCode(); assertTrue(result != -1); }