public IActionResult RemoveUsers(string id)
        {
            var usersWithRole = _userManager.GetUsersInRoleAsync(id).Result.ToList();

            var model = new AddToRoleVM {
                users = usersWithRole, RoleName = id
            };

            return(View(model));
        }
        public IActionResult AddUsers(string id)
        {
            var usersWithRole    = _userManager.GetUsersInRoleAsync(id).Result.ToList();
            var usersWithoutRole = _userManager.Users.Where(b => !usersWithRole.Contains(b)).ToList();

            var model = new AddToRoleVM {
                users = usersWithoutRole, RoleName = id
            };

            return(View(model));
        }