public RestHttpClientTests()
        {
            _loggerFactory = new StubLoggerFactory(_loggers);
            RestHttpClient.ResetAccessToken();
            RestHttpClient.ResetAuthorizationRequestHandler();

            _configuration.ConfigHeaders(new RestHttpClientHeaderOptions()
            {
                ForwardedHeaders = new HashSet <string>()
                {
                    TraceEventIdHeader, UserspaceIdHeader
                }
            });
        }