/**
  * Queues up mock HTTP Response objects for a client
  *
  * @param SdkClientInterface $client
  * @param Response[]         $responses
  * @param bool               $readBodies
  *
  * @return SdkClientInterface
  * @throws \InvalidArgumentException
  */
 private function addMockResponses($client, array $responses, $readBodies = true)
 {
     $mock = new Mock($responses, $readBodies);
     $client->getHttpClient()->getEmitter()->attach($mock);
     return $client;
 }