Iterable<ArchUnitExtension> getAll() {
        return extensions.get();
    }
@Test
    public void loads_multiple_extensions() {
        testServicesFile.addService(TestExtension.class);
        testServicesFile.addService(DummyTestExtension.class);
        testServicesFile.addService(YetAnotherDummyTestExtension.class);

        Iterable<ArchUnitExtension> extensions = extensionLoader.getAll();

        assertThat(extensions)
                .hasSize(3)
                .hasAtLeastOneElementOfType(TestExtension.class)
                .hasAtLeastOneElementOfType(DummyTestExtension.class)
                .hasAtLeastOneElementOfType(YetAnotherDummyTestExtension.class);
    }