@Test
 public void testDistanceRobustness() {
   distanceMetricTest.testRobustness();
 }
 @Test
 public void testDistance() {
   distanceMetricTest.testDistance();
 }
 @Test
 public void testDistanceEmptyArguments() {
   distanceMetricTest.testEmptyArguments();
 }
 @Test
 public void testDistanceCommutativity() {
   distanceMetricTest.testCommutativity();
 }
 @Test
 public void testDistanceNullArguments() {
   distanceMetricTest.testNullArguments();
 }