/// <summary>Process the operation get ws binding token described by response.</summary>
        /// <param name="context">          [in,out] The context.</param>
        /// <param name="response">         [in,out] The response.</param>
        /// <param name="previousComponent">The previous component.</param>
        internal static void ProcessOperationGetWsBindingToken(
            ref HttpContext context,
            ref HttpResponseMessage response,
            string previousComponent)
        {
            List <string> ids = new List <string>();

            if (previousComponent != "Subscription")
            {
                ids.Add(previousComponent);
            }
            else
            {
                try
                {
                    using (TextReader reader = new StreamReader(context.Request.Body))
                    {
                        string requestContent = reader.ReadToEndAsync().Result;

                        Parameters opParams = _fhirParser.Parse <Parameters>(requestContent);

                        foreach (Parameters.ParameterComponent param in opParams.Parameter)
                        {
                            if (param.Name == "ids")
                            {
                                ids.Add((param.Value as Id).ToString());
                            }
                        }
                    }
                }
                catch (Exception ex)
                {
                    response.StatusCode = HttpStatusCode.BadRequest;
                    response.Content    = new StringContent("Caught exception: " + ex.Message);
                    return;
                }
            }

            foreach (string id in ids)
            {
                if (!SubscriptionManagerR4.Exists(id))
                {
                    response.StatusCode = HttpStatusCode.BadRequest;
                    response.Content    = new StringContent($"Invalid subscription id: {id}");
                    return;
                }
            }

            SubscriptionWsBindingToken token = SubscriptionWsBindingToken.GetTokenR4(ids);

            WebsocketManager.RegisterToken(token);

            Parameters parameters = new Parameters();

            parameters.Add("token", new FhirString(token.Token.ToString()));
            parameters.Add("expiration", new FhirDateTime(new DateTimeOffset(token.ExpiresAt)));
            parameters.Add("subscriptions", new FhirString(string.Join(',', ids)));

            ProcessorUtils.SerializeR4(ref response, parameters);
        }