/**
  * @param Configuration $configuration
  * @param HttpClientInterface|null $client
  */
 public function __construct(Configuration $configuration, HttpClientInterface $client = null)
 {
     $this->configuration = $configuration;
     if ($client === null) {
         $this->client = new \GuzzleHttp\Client($this->configuration->getClientConfiguration());
     } else {
         $this->client = $client;
     }
 }
 /**
  * @test
  */
 public function clientConfigurationIsSetAndRetrievedCorrectly()
 {
     $clientConfiguration = ['foo' => 'bar'];
     $configuration = new Configuration($this->mergeConfigurationWithMinimalConfiguration(['clientConfiguration' => $clientConfiguration]));
     $this->assertEquals($clientConfiguration, $configuration->getClientConfiguration());
 }