@Override
    public void loadGlue(Glue glue, List<URI> gluePaths) {
        gluePaths.stream()
                .filter(gluePath -> CLASSPATH_SCHEME.equals(gluePath.getScheme()))
                .map(ClasspathSupport::packageName)
                .map(classFinder::scanForClassesInPackage)
                .flatMap(Collection::stream)
                .filter(InjectorSource.class::isAssignableFrom)
                .distinct()
                .forEach(container::addClass);
    }
@Test
    void finds_injector_source_impls_once_by_classpath_url() {
        GuiceBackend backend = new GuiceBackend(factory, classLoader);
        backend.loadGlue(glue, asList(URI.create("classpath:io/cucumber/guice/integration"),
            URI.create("classpath:io/cucumber/guice/integration")));
        verify(factory, times(1)).addClass(YourInjectorSource.class);
    }