code: static public void assertNull(Object object) {
      		String message = "Expected: <null> but was: " + String.valueOf(object);
      		assertNull(message, object);
      	}
docs: Asserts that an object is null. If it isn't an {@link AssertionError} is
  thrown.
  Message contains: Expected: null but was: object
  
  @param object
  Object to check or <code>null</code>