public TeacherUser AuthenticateTeacher(string username, string password)
        {
            TeacherUser teacherUser = null;

            password = HashSHA256(password);

            try
            {
                if (1 == _userAccess.VerifyUsernamePasswordTeacher(username, password))
                {
                    teacherUser = _userAccess.GetTeacherByEmail(username);

                    if (password == HashSHA256("newuser"))
                    {
                        teacherUser.TeacherUsers.Add("New User");
                    }
                }
                else
                {
                    throw new ApplicationException("The Teacher you requested was not found.");
                }
            }
            catch (Exception ex)
            {
                throw new ApplicationException("User not validated.", ex);
            }

            return(teacherUser);
        }