@Test
public void shouldCallRegisterUserServiceToRegisterUser() throws IOException {

    RegisterUnverifiedUserAsyncTask registerUserTask = new RegisterUnverifiedUserAsyncTask(registerUserService, user, context);
    given(registerUserService.register(user)).willReturn(new FluentResponse(new TestHttpResponse(201, "created")));
    assertThat(registerUserTask.doInBackground("url"), is(true));
}