public OrdersService(IConfiguration configuration, IGenericRestClient restClient)
 {
     _configuration = configuration ?? throw new ArgumentNullException(nameof(configuration));
     _restClient    = restClient ?? throw new ArgumentNullException(nameof(restClient));
     _restClient.Configure(GetApiUrl, GetApiKey);
 }
 public void GenericRestClient_Configure_throw_exception_when_Url_isNull()
 {
     //Act && Assert
     Assert.Throws <ArgumentNullException>(() => _sut.Configure(null, "1234"));
 }