@Test
  public void findByUserManagerId() {
    @SuppressWarnings("unchecked")
    Page<User> requestedPage = mock(Page.class);

    when(userRepository.findByUserManagerId(any(Long.class), any(Pageable.class)))
        .thenReturn(requestedPage);

    userService.findByUserManagerId(0L, 0, 5);

    verify(userRepository, times(1)).findByUserManagerId(any(Long.class), any(Pageable.class));
  }