Microsoft.Azure.WebJobs.Script.WebHost.WebHooks.WebHookReceiverManager.GetClientID C# (CSharp) Method

        private static string GetClientID(HttpRequestMessage request)
        {
            string keyValue = null;
            IEnumerable<string> headerValues;
            if (request.Headers.TryGetValues(FunctionsClientIdHeaderName, out headerValues))
            {
                keyValue = headerValues.FirstOrDefault();
            }
            else
            {
                keyValue = request.GetQueryNameValuePairs()
                      .FirstOrDefault(q => string.Compare(q.Key, FunctionsClientIdQueryStringName, StringComparison.OrdinalIgnoreCase) == 0)
                      .Value;
            }

            return keyValue;
        }