Microsoft.Identity.Client.Internal.WsTrustResponse.ReadErrorResponse C# (CSharp) Method

        public static string ReadErrorResponse(XDocument responseDocument, CallState callState)
        {
            string errorMessage = null;

            try
            {
                XElement body = responseDocument.Descendants(XmlNamespace.SoapEnvelope + "Body").FirstOrDefault();

                if (body != null)
                {
                    XElement fault = body.Elements(XmlNamespace.SoapEnvelope + "Fault").FirstOrDefault();
                    if (fault != null)
                    {
                        XElement reason = fault.Elements(XmlNamespace.SoapEnvelope + "Reason").FirstOrDefault();
                        if (reason != null)
                        {
                            XElement text = reason.Elements(XmlNamespace.SoapEnvelope + "Text").FirstOrDefault();
                            if (text != null)
                            {
                                using (var reader = text.CreateReader())
                                {
                                    reader.MoveToContent();
                                    errorMessage = reader.ReadInnerXml();
                                }
                            }
                        }
                    }
                }
            }
            catch (XmlException ex)
            {
                PlatformPlugin.Logger.Error(callState, ex);
                throw new MsalException(MsalError.ParsingWsTrustResponseFailed, ex);
            }

            return errorMessage;
        }

        public static async Task <WsTrustResponse> SendRequestAsync(WsTrustAddress wsTrustAddress, UserCredential credential, CallState callState)
        {
            HttpClientWrapper request = new HttpClientWrapper(wsTrustAddress.Uri.AbsoluteUri, callState);

            request.ContentType = "application/soap+xml";
            if (credential.UserAuthType == UserAuthType.IntegratedAuth)
            {
                SetKerberosOption(request);
            }

            StringBuilder   messageBuilder = BuildMessage(DefaultAppliesTo, wsTrustAddress, credential);
            WsTrustResponse wstResponse;

            try
            {
                request.BodyParameters = new StringRequestParameters(messageBuilder);
                IHttpWebResponse response = await request.GetResponseAsync().ConfigureAwait(false);

                wstResponse = WsTrustResponse.CreateFromResponse(response.ResponseStream, wsTrustAddress.Version);
            }
            catch (WebException ex)
            {
                PlatformPlugin.Logger.Error(callState, ex);
                string errorMessage;

                try
                {
                    XDocument responseDocument = WsTrustResponse.ReadDocumentFromResponse(ex.Response.GetResponseStream());
                    errorMessage = WsTrustResponse.ReadErrorResponse(responseDocument, callState);
                }
                catch (MsalException)
                {
                    errorMessage = "See inner exception for detail.";
                }

                throw new MsalServiceException(
                          MsalError.FederatedServiceReturnedError,
                          string.Format(MsalErrorMessage.FederatedServiceReturnedErrorTemplate, wsTrustAddress.Uri, errorMessage),
                          null,
                          ex);
            }

            return(wstResponse);
        }