@Test
public void getBookmarksOfUserReturnsAllBookmarks() {

    // given
    given(userMock.getBookmarks()).willReturn(Collections.singleton(projectMock));
    // when
    List<Project> actualBookmarks = bookmarkService.getBookmarksOfUser(userMock);
    // then
    assertThat(actualBookmarks).containsExactly(projectMock);
}