@Override
    public Mono<ExtensionStore> fetchByName(String name) {
        return repository.findById(name);
    }
@Test
    void fetchByName() {
        var expectedExtension =
            new ExtensionStore("/registry/posts/hello-world", "this is post".getBytes(), 1L);

        when(repository.findById("/registry/posts/hello-halo"))
            .thenReturn(Mono.just(expectedExtension));

        var gotExtension = client.fetchByName("/registry/posts/hello-halo").blockOptional();
        assertTrue(gotExtension.isPresent());
        assertEquals(expectedExtension, gotExtension.get());
    }