### Question:
MultiRabbitConnectionFactoryWrapper { public void addConnectionFactory(final String key, final ConnectionFactory connectionFactory) { addConnectionFactory(key, connectionFactory, null, null); }  void setDefaultConnectionFactory(final ConnectionFactory connectionFactory); void addConnectionFactory(final String key, final ConnectionFactory connectionFactory); void addConnectionFactory(final String key,
                                     final ConnectionFactory connectionFactory,
                                     final AbstractRabbitListenerContainerFactory containerFactory); void addConnectionFactory(final String key,
                                     final ConnectionFactory connectionFactory,
                                     final AbstractRabbitListenerContainerFactory containerFactory,
                                     final RabbitAdmin rabbitAdmin);  }### Answer:
@Test public void shouldNotAddConnectionFactoryWithEmptyKey() { exception.expect(IllegalArgumentException.class); exception.expectMessage("Key may not be null or empty"); wrapper().addConnectionFactory("", connectionFactory, containerFactory, rabbitAdmin); }
@Test public void shouldNotAddNullConnectionFactory() { exception.expect(IllegalArgumentException.class); exception.expectMessage("ConnectionFactory may not be null"); wrapper().addConnectionFactory(DUMMY_KEY, null, containerFactory, rabbitAdmin); }