@Test(expected = IllegalArgumentException.class)
public void testDuplicateLabel() throws Exception {

	final ConfigurationOptionProvider optionProvider = TestConfigurationOptionProvider.of(
			ConfigurationOption.stringOption().key("foo").description("Foo").build(),
			ConfigurationOption.stringOption().key("foo").label("Bar").build());
	ConfigurationRegistry.builder().addOptionProvider(optionProvider).build();
}