public void LeaveGroup()
        {
            _provider.DeleteUserFromGroup(_user, _group);
            GroupListPage groupListPage = new GroupListPage(_user);

            groupListPage.Init();
        }
        public void ShowGroups()
        {
            GroupListPage groupsPage = new GroupListPage(_user);

            groupsPage.Init();
        }
        public void BackToGroups()
        {
            GroupListPage groupListPage = new GroupListPage(_user);

            groupListPage.Init();
        }