public void GetCourseStudents_CourseFound_ListStudents()
        {
            // Arrange
            var id       = Guid.NewGuid();
            var students = new List <Student>()
            {
                new Student {
                    Id = Guid.NewGuid()
                }
            };

            CoursesRepository.GetStudents(id).Returns(new ListResult <Student> {
                Return = students
            });

            // Act
            var result = _service.GetCourseStudents(id);

            // Assert
            Assert.That(result, Is.Not.Null);
            Assert.That(result.Succeed, Is.True);
            Assert.That(result.Return, Is.Not.Null.And.Not.Empty);
        }