public HttpClient CreateClient(RequestData requestData)
        {
            if (requestData == null)
            {
                throw new ArgumentNullException(nameof(requestData));
            }

            var key     = HttpConnection.GetClientKey(requestData);
            var handler = CreateHandler(key, requestData);
            var client  = new HttpClient(handler, disposeHandler: false);

            client.Timeout = requestData.RequestTimeout;
            return(client);
        }