@Test
public void getAttachmentsOfConversation() throws Exception {

    server.enqueue(new MockResponse().setBody(file("messages/attachments.json")));
    Response<List<MessageAttachment>, HttpError> response = resource.getAttachmentsOfConversation("123").execute();
    assertThat(response.body().size()).isEqualTo(1);
    assertThat(response.body().get(0).getId()).isEqualTo("4321_xyza");
}