public static void TestOperations()
        {
            var context = new SoftUniEntities();

            Employee employee = new Employee()
            {
                FirstName = "Denis1",
                LastName = "Neychev",
                JobTitle = "Zidaro-mazach",
                DepartmentID = 1,
                ManagerID = 6,
                HireDate = DateTime.Now,
                Salary = 999
            };

            Employee.Add(employee);

            context.SaveChanges();

            Console.WriteLine(employee.EmployeeID);

            employee.FirstName = employee.FirstName + '.';

            Employee.Modify(employee);

            context.SaveChanges();

            Employee.Delete(employee);

            context.SaveChanges();
        }
        public static void Add(Employee employee)
        {
            var context = new SoftUniEntities();

            context.Employees.Add(employee);

            context.SaveChanges();
        }
        public static void Modify(Employee employee)
        {
            var context = new SoftUniEntities();

            Employee EmpModify = context.Employees.Find(employee.EmployeeID);

            context.Entry(EmpModify).CurrentValues.SetValues(employee);

           context.SaveChanges();
        }
        public static void Delete(Employee employee)
        {
            var context = new SoftUniEntities();

            var entry = context.Entry(employee);

            if (entry.State == EntityState.Detached)
            {
                context.Employees.Attach(employee);
            }
               
            context.Employees.Remove(employee);
            
            context.SaveChanges();
        }