@Test(expectedExceptions = DescriptorValidationFailedException.class)
public void testLoadExternalClassShouldThrowDescriptorValidationFailedExceptionWhenNeitherBeanNorClassWasFound() throws ClassNotFoundException {

    //GIVEN
    given(beanRegistryService.getBean(BEAN_NAME, INTERFACE_TO_CAST)).willThrow(new NoSuchBeanDefinitionException("error"));
    Collection<File> jarFiles = new ArrayList<>();
    given(fileUtils.listFiles(folder, "jar")).willReturn(jarFiles);
    given(packageBasedClassFinder.findFirstOf(INTERFACE_TO_CAST, PACKAGE_NAME)).willThrow(new ClassNotFoundException());
    //WHEN
    underTest.loadExternalClass(PACKAGE_NAME, JAR_FOLDER_PATH, INTERFACE_TO_CAST);
    //THEN exception is thrown
}