public User DeleteUserFromRole(int userId, int roleId)
        {
            IRoleRepository<User, Role, RolePermission> roleRepository = new EntityRoleRepository();

            User user = GetUser(userId);
            Role role = roleRepository.FindRole(roleId);

            if (user == null)
                throw new NullUserException("User is null.");

            if (role == null)
                throw new NullRoleException("Role is null.");

            UserRole userRole = GetUserRole(user, role);
            theEntities.DeleteObject(userRole);
            theEntities.SaveChanges();

            return user;
        }
        private UserRole AddUserToNotConfirmedUserRole(User aUser, string aNotConfirmedRoleName)
        {
            IRoleRepository<User, Role, RolePermission> roleRepository = new EntityRoleRepository();
            Role notConfirmedUserRole = roleRepository.GetRoleByName(aNotConfirmedRoleName);

            return AddUserToRole(aUser, notConfirmedUserRole);
        }