public void AddItemsTest()
        {
            var repo  = new StudentsRepository(_context);
            var item1 = new Student
            {
                FirstName     = "John",
                MiddleName    = "Anthony",
                LastName      = "Cena",
                Address       = "West Newbury",
                Birthday      = new DateTime(1973, 04, 23),
                Email         = "*****@*****.**",
                LogbookNumber = 4355,
                Group         = _context.Groups.FirstOrDefault()
            };
            var item2 = new Student
            {
                FirstName     = "Paul",
                MiddleName    = "Unknown",
                LastName      = "Jacobson",
                Address       = "Manchester",
                Birthday      = new DateTime(1968, 11, 02),
                Email         = "*****@*****.**",
                LogbookNumber = 4299,
                Group         = _context.Groups.FirstOrDefault()
            };

            Student[] items = new Student[] { item1, item2 };

            repo.AddItems(items);
            var newitem1 = _context.Students.FirstOrDefault(x => x.LogbookNumber == 4355);
            var newitem2 = _context.Students.FirstOrDefault(x => x.LogbookNumber == 4299);

            Assert.AreEqual(items[0].LogbookNumber, newitem1.LogbookNumber);
            Assert.AreEqual(items[0].FirstName, newitem1.FirstName);
            Assert.AreEqual(items[0].MiddleName, newitem1.MiddleName);
            Assert.AreEqual(items[0].LastName, newitem1.LastName);
            Assert.AreEqual(items[0].Address, newitem1.Address);
            Assert.AreEqual(items[0].Birthday, newitem1.Birthday);
            Assert.AreEqual(items[0].Email, newitem1.Email);

            Assert.AreEqual(items[1].LogbookNumber, newitem2.LogbookNumber);
            Assert.AreEqual(items[1].FirstName, newitem2.FirstName);
            Assert.AreEqual(items[1].MiddleName, newitem2.MiddleName);
            Assert.AreEqual(items[1].LastName, newitem2.LastName);
            Assert.AreEqual(items[1].Address, newitem2.Address);
            Assert.AreEqual(items[1].Birthday, newitem2.Birthday);
            Assert.AreEqual(items[1].Email, newitem2.Email);

            _context.Students.Remove(item1);
            _context.Students.Remove(item2);
        }