assertEquals( 0, comparator.compare( null, null ) );
assertEquals( 0, comparator.compare( 1L, 1L ) );
assertEquals( 0, comparator.compare( -1L, -1L ) );
assertEquals( 1, comparator.compare( 1L, null ) );
assertEquals( 1, comparator.compare( 2L, 1L ) );
assertEquals( 1, comparator.compare( 3L, 1L ) );
assertEquals( 1, comparator.compare( 1L, -1L ) );
assertEquals( -1, comparator.compare( null, 1L ) );
assertEquals( -1, comparator.compare( 1L, 2L ) );
assertEquals( -1, comparator.compare( -1L, 1L ) );