public function testChainSerializeDeserialize()
 {
     $config_path = __DIR__ . '/../sphinx/conf/valid.example.conf';
     $plain_config = file_get_contents($config_path);
     $referenceHash = md5((string) Configuration::fromString($plain_config, eVersion::V_2_2_10()));
     $config = Configuration::fromString($plain_config, eVersion::V_2_2_10());
     $config = Configuration::fromArray($config->toArray(), eVersion::V_2_2_10());
     $config = Configuration::fromJson($config->toJson(), eVersion::V_2_2_10());
     $config = Configuration::fromString((string) $config, eVersion::V_2_2_10());
     $hash = md5((string) $config);
     static::assertEquals($referenceHash, $hash);
 }