public async Task <SendMessageResponse> sendMessage(OutgoingPushMessageList bundle)
        //throws IOException
        {
            try
            {
                String responseText = await makeRequest(String.Format(MESSAGE_PATH, bundle.getDestination()), "PUT", JsonUtil.toJson(bundle));

                if (responseText == null)
                {
                    return(new SendMessageResponse(false));
                }
                else
                {
                    return(JsonUtil.fromJson <SendMessageResponse>(responseText));
                }
            }
            catch (Exception nfe)
            {
                throw new UnregisteredUserException(bundle.getDestination(), nfe);
            }
        }
        public async Task<SendMessageResponse> sendMessage(OutgoingPushMessageList bundle)
        //throws IOException
        {
            try
            {
                String responseText =
                    await
                        makeRequest(String.Format(MESSAGE_PATH, bundle.getDestination()), "PUT", JsonUtil.toJson(bundle));

                if (responseText == null) return new SendMessageResponse(false);
                else return JsonUtil.fromJson<SendMessageResponse>(responseText);
            }
            catch (NotFoundException nfe)
            {
                throw new UnregisteredUserException(bundle.getDestination(), nfe);
            }
            catch (PushNetworkException e)
            {
                throw;
            }
            catch (Exception e)
            {
                Debug.WriteLine("Unexpected exeption");
                throw;
            }
        }