### Question:
XsuaaTokenFlows implements Serializable { public RefreshTokenFlow refreshTokenFlow() { return new RefreshTokenFlow(oAuth2TokenService, endpointsProvider, clientCredentials); } XsuaaTokenFlows(OAuth2TokenService oAuth2TokenService,
			OAuth2ServiceEndpointsProvider endpointsProvider, ClientCredentials clientCredentials); UserTokenFlow userTokenFlow(); ClientCredentialsTokenFlow clientCredentialsTokenFlow(); RefreshTokenFlow refreshTokenFlow(); PasswordTokenFlow passwordTokenFlow();  }### Answer:
@Test public void startRefreshTokenFlow() { RefreshTokenFlow flow = cut.refreshTokenFlow(); assertNotNull("RefreshTokenFlow must not be null.", flow); }