public async Task FindById_ReturnSubjectDetailModel()
        {
            //Arrange
            var subjectsList = await subjectService.GetAllSubjects();

            var lastSubject = subjectsList[subjectsList.Count - 1];

            //Act
            var result = await subjectService.FindById(lastSubject.Id);

            //Assert
            Assert.IsInstanceOfType(result, typeof(SubjectDetailsModel));
        }