### Question:
LongPair implements Comparable<LongPair> { @Override public int compareTo(LongPair other) { if (other == null) { return 1; } if (other.first == this.first) { return (int) (this.second - other.second); } return (int) (this.first - other.first); } LongPair(long first, long second); @Override int hashCode(); @Override boolean equals(Object obj); long getFirst(); void setFirst(long first); long getSecond(); void setSecond(long second); @Override int compareTo(LongPair other);  }### Answer:
@Test public void testCompareTo() { CompareToTester<LongPair> compareToTester = new CompareToTester<>(new LongPair(4, 10)); compareToTester.performCompareToTestEqual(new LongPair(4, 10)); compareToTester.performComparetoTestNotEqual(new LongPair(42, 23)); compareToTester.performCompareToTestGreater(new LongPair(5, 9), new LongPair(4, 11)); compareToTester.performCompareToTestNotGreater(new LongPair(3, 11)); compareToTester.performCompareToTestSmaller(new LongPair(3, 10), new LongPair(4, 9)); compareToTester.performCompareToTestNotSmaller(new LongPair(5, 2)); }