public BraintreeHttpClient(string merchantServerURL, UploadStringCompletedEventHandler handler) { _uri = new Uri(merchantServerURL, UriKind.Absolute); _webClient = new WebClient(); _webClient.Headers["Content-Type"] = "application/x-www-form-urlencoded"; _webClient.Encoding = Encoding.UTF8; _webClient.UploadStringCompleted += handler; }