### Question:
ClientCredentialsTokenFlow { public ClientCredentialsTokenFlow scopes(@Nonnull String... scopes) { Assertions.assertNotNull(scopes, "Scopes must not be null!"); this.scopes = Arrays.asList(scopes); return this; } ClientCredentialsTokenFlow(OAuth2TokenService tokenService, OAuth2ServiceEndpointsProvider endpointsProvider,
			ClientCredentials clientCredentials); ClientCredentialsTokenFlow attributes(Map<String, String> additionalAuthorizationAttributes); ClientCredentialsTokenFlow subdomain(String subdomain); ClientCredentialsTokenFlow scopes(@Nonnull String... scopes); ClientCredentialsTokenFlow disableCache(boolean disableCache); OAuth2TokenResponse execute();  }### Answer:
@Test public void execute_withScopesSetToNull_throwsException() throws OAuth2ServiceException, TokenFlowException { assertThatThrownBy(() -> cut.scopes(null)).isInstanceOf(IllegalArgumentException.class); }