@Test
public void createPost() throws Exception {

    server.enqueue(new MockResponse().setBody(file("groups/create_post.json")));
    Response<Post, HttpError> response =
          resource.createPost("My funny Post", "A funny rabbit goes to a hole", "213").execute();
    assertThat(response.body()).isNotNull();
    assertThat(response.body().title()).isEqualTo("My funny Post");
    assertThat(response.body().author().displayName()).isEqualTo("Vladimir");
}