@Test
public void throwExceptionIfConnectionFactoryReturnNull() throws Exception {

	RMQConnectionConfig connectionConfig = Mockito.mock(RMQConnectionConfig.class);
	ConnectionFactory connectionFactory = Mockito.mock(ConnectionFactory.class);
	Connection connection = Mockito.mock(Connection.class);
	Mockito.when(connectionConfig.getConnectionFactory()).thenReturn(connectionFactory);
	Mockito.when(connectionFactory.newConnection()).thenReturn(connection);
	Mockito.when(connection.createChannel()).thenReturn(null);
	RMQSource<String> rmqSource = new RMQSource<>(
		connectionConfig, "queueDummy", true, new StringDeserializationScheme());
	try {
		rmqSource.open(new Configuration());
	} catch (RuntimeException ex) {
		assertEquals("None of RabbitMQ channels are available", ex.getMessage());
	}
}