### Question:
IntComparator implements Comparator<Integer> { private IntComparator() { } private  IntComparator(); int compare( Integer integer1, Integer integer2 ); static final IntComparator INSTANCE; }### Answer:
@Test public void testIntComparator() { IntComparator comparator = IntComparator.INSTANCE; assertEquals( 0, comparator.compare( null, null ) ); assertEquals( 0, comparator.compare( 1, 1 ) ); assertEquals( 0, comparator.compare( -1, -1 ) ); assertEquals( 1, comparator.compare( 1, null ) ); assertEquals( 1, comparator.compare( 2, 1 ) ); assertEquals( 1, comparator.compare( 3, 1 ) ); assertEquals( 1, comparator.compare( 1, -1 ) ); assertEquals( -1, comparator.compare( null, 1 ) ); assertEquals( -1, comparator.compare( 1, 2 ) ); assertEquals( -1, comparator.compare( -1, 1 ) ); }