/// <summary>
        /// Serializes the TempHumidityEvent to JSON and sends it to the Event Hub's REST API
        /// </summary>
        /// <param name="tempHumidityEvent"></param>
        /// <returns></returns>
        private async Task SendEventAsync(TempHumidityEvent tempHumidityEvent)
        {
            // Convert TempHumidityEvent to JSON
            var json    = JsonConvert.SerializeObject(tempHumidityEvent);
            var content = new StringContent(json);

            // Send event
            var response = await httpClient.PostAsync(baseAddress + "/dachautemp/messages", content);

            if (response.StatusCode == HttpStatusCode.Unauthorized)
            {
                // Maybe token expired available. Renew and try again
                RefreshAccessToken();

                // Try again
                content  = new StringContent(json);
                response = await httpClient.PostAsync(baseAddress + "/dachautemp/messages", content);
            }

            // Check if everything went fine
            if (!response.IsSuccessStatusCode)
            {
                throw new UnauthorizedAccessException("Could not connect to Azure Event Hub. Access denied.");
            }
        }
        /// <summary>
        /// Sends a new combination of temperature, humidity and a time stamp to the Event Hub
        /// </summary>
        /// <param name="temperature">Current temperature</param>
        /// <param name="humidity">Current humidity</param>
        /// <returns></returns>
        public async Task SendTempAndHumidityAsync(double temperature, double humidity)
        {
            // Round to full seconds and milliseconds
            var now = DateTime.Now.ToUniversalTime();

            now = now.AddSeconds(now.Second * -1).AddMilliseconds(now.Millisecond * -1);

            var tempHumidityEvent = new TempHumidityEvent {
                DateTime = now, Temperature = temperature, Humidity = humidity
            };

            await SendEventAsync(tempHumidityEvent);
        }