public void GetFinishedChaptersTest_Passt(int resultCount, List <UserLesson> finishedLessons, List <Chapter> allChapters)
        {
            if (allChapters == null)
            {
                _coursesService.Setup(x => x.GetChapters()).Returns((IQueryable <Chapter>)null);
            }
            else
            {
                _coursesService.Setup(x => x.GetChapters()).Returns(allChapters.AsQueryable());
            }

            var result = _resultsManager.GetFinishedChapters(finishedLessons);

            Assert.True(result != null);
            Assert.True(result.Count == resultCount);
        }