@Test
 public void findingConstructorQuietlyGivesNullIfNoSuchConstructor() {
   assertNull(findConstructor(Integer.class, Object.class));
 }
 @Test
 public void anInterfaceWithNoMethodsIsNotASingleAbstractMethodType() {
   assertNull(singleAbstractMethodOf(Serializable.class));
 }
 @Test
 public void anInterfaceThatOverridesToStringIsNotASingleAbstractMethodType() throws Exception {
   assertNull(singleAbstractMethodOf(OverridingToString.class));
 }
 @Test
 public void aClassIsNotASingleAbstractMethodType() {
   assertNull(singleAbstractMethodOf(String.class));
 }