code: public IMockObject asMock(Object object) {
      if (!isMock(object)) {
        throw new IllegalArgumentException("Not a mock object: " + object.toString());
      }
  
      ISpockMockObject handle = (ISpockMockObject) object;
      return handle.$spock_get();
    }
docs: Returns information about a mock object.
  
  @param object a mock object
  
  @return information about the mock object
  
  @throws IllegalArgumentException if the given object is not a mock object