/// <summary>
 /// Initializes the factory.
 /// </summary>
 private void Initialize()
 {
     if (!this.WebsiteUrl.IsNullOrWhiteSpace())
     {
         return;
     }
     this.WebsiteUrl = PayPalApiHelper.GetBaseWebsiteUrl();
 }
 /// <summary>
 /// Initializes a new instance of the <see cref="PayPalExpressCheckoutService"/> class.
 /// </summary>
 /// <param name="settings">
 /// The settings.
 /// </param>
 public PayPalExpressCheckoutService(PayPalProviderSettings settings)
     : base(settings)
 {
     _websiteUrl      = PayPalApiHelper.GetBaseWebsiteUrl();
     _responseFactory = new ExpressCheckoutResponseFactory();
 }