/// <summary>
        /// Loads the metadata and converts it into an EdmModel that is then used by a dataservice context
        /// This allows the user to use the DataServiceContext directly without having to manually pass an IEdmModel in the Format
        /// </summary>
        /// <returns>A service model to be used in format tracking</returns>
        internal IEdmModel LoadServiceModelFromNetwork()
        {
            HttpWebRequestMessage    httpRequest;
            BuildingRequestEventArgs requestEventArgs = null;

            // test hook for injecting a network request to use instead of the default
            if (InjectMetadataHttpNetworkRequest != null)
            {
                httpRequest = InjectMetadataHttpNetworkRequest();
            }
            else
            {
                requestEventArgs = new BuildingRequestEventArgs(
                    "GET",
                    context.GetMetadataUri(),
                    null,
                    null,
                    context.HttpStack);

                // fire the right events if they exist to allow user to modify the request
                if (context.HasBuildingRequestEventHandlers)
                {
                    requestEventArgs = context.CreateRequestArgsAndFireBuildingRequest(
                        requestEventArgs.Method,
                        requestEventArgs.RequestUri,
                        requestEventArgs.HeaderCollection,
                        requestEventArgs.ClientHttpStack,
                        requestEventArgs.Descriptor);
                }

                DataServiceClientRequestMessageArgs args = new DataServiceClientRequestMessageArgs(
                    requestEventArgs.Method,
                    requestEventArgs.RequestUri,
                    context.UseDefaultCredentials,
                    context.UsePostTunneling,
                    requestEventArgs.Headers);

                httpRequest = new HttpWebRequestMessage(args);
            }

            Descriptor descriptor = requestEventArgs != null ? requestEventArgs.Descriptor : null;

            // fire the right events if they exist
            if (context.HasSendingRequest2EventHandlers)
            {
                SendingRequest2EventArgs eventArgs = new SendingRequest2EventArgs(
                    httpRequest,
                    descriptor,
                    false);

                context.FireSendingRequest2(eventArgs);
            }

            Task <IODataResponseMessage> asyncResponse =
                Task <IODataResponseMessage> .Factory.FromAsync(httpRequest.BeginGetResponse, httpRequest.EndGetResponse,
                                                                httpRequest);

            IODataResponseMessage response = asyncResponse.GetAwaiter().GetResult();

            ReceivingResponseEventArgs responseEvent = new ReceivingResponseEventArgs(response, descriptor);

            context.FireReceivingResponseEvent(responseEvent);

            using (StreamReader streamReader = new StreamReader(response.GetStream()))
                using (XmlReader xmlReader = XmlReader.Create(streamReader))
                {
                    return(CsdlReader.Parse(xmlReader));
                }
        }