public async Task ATS_DefaultAccount_Async()
        {
            string homeAccId = $"{TestConstants.Uid}.{TestConstants.Utid}";

            // Arrange
            using (var harness = CreateTestHarness())
            {
                var wamAccountProvider = new WebAccountProvider("id", "*****@*****.**", null);
                var requestParams      = harness.CreateAuthenticationRequestParameters(TestConstants.AuthorityHomeTenant); // AAD authority, no account
                var webTokenRequest    = new WebTokenRequest(wamAccountProvider);
                var atsParams          = new AcquireTokenSilentParameters();
                _webAccountProviderFactory.GetAccountProviderAsync(null).ReturnsForAnyArgs(Task.FromResult(wamAccountProvider));
                var webTokenResponseWrapper = Substitute.For <IWebTokenRequestResultWrapper>();
                webTokenResponseWrapper.ResponseStatus.Returns(WebTokenRequestStatus.Success);
                var webTokenResponse = new WebTokenResponse();
                webTokenResponseWrapper.ResponseData.Returns(new List <WebTokenResponse>()
                {
                    webTokenResponse
                });

                _aadPlugin.CreateWebTokenRequestAsync(
                    wamAccountProvider,
                    requestParams,
                    isForceLoginPrompt: false,
                    isAccountInWam: false,
                    isInteractive: false)
                .Returns(Task.FromResult(webTokenRequest));

                _wamProxy.GetTokenSilentlyForDefaultAccountAsync(webTokenRequest).
                Returns(Task.FromResult(webTokenResponseWrapper));

                _aadPlugin.ParseSuccesfullWamResponse(webTokenResponse).Returns(_msalTokenResponse);

                // Act
                var result = await _wamBroker.AcquireTokenSilentDefaultUserAsync(requestParams, atsParams).ConfigureAwait(false);

                // Assert
                Assert.AreSame(_msalTokenResponse, result);
                await _aadPlugin.Received(1).CreateWebTokenRequestAsync(wamAccountProvider,
                                                                        requestParams,
                                                                        isForceLoginPrompt: false,
                                                                        isAccountInWam: false,
                                                                        isInteractive: false).ConfigureAwait(false);
            }
        }