anchor.diff:              child: new Text(
                 "Delete",
                 style: new TextStyle(color: Colors.red),),
  -            onPressed: () => setState(() {
  -              // TODO remove him from the database
  -              _friendUsers.remove(user);
  -            })),)
  +            onPressed: () {
  +              setState(() => _friendUsers.remove(user));
  +              SharedPreferences.getInstance().then((sp) =>
  +                  sp.setStringSet(DatabaseKeys.FRIENDS, _friendUsers.map((u) => u.username).toSet()));
  +            }),)
         ],)).toList();
       _friendsView.add(new ListTile(
         isThreeLine: true,
  
positive.code:   }
  
    _performChangeUser(String _json) {
      _user = _json2user(_json, onError: (msg) => _me.displayWhenEmpty = msg);
    }
  
    _performChangeFriends(List<String> _allJson) {
      _allJson
          .map(_json2user)
          .where((o) => null != o)
          .forEach(_friendUsers.add);
    }
  
    bool _addFriend(String _json) {
      CodeWarsUser friend = _json2user(_json);
      if (null != friend) {
        _friendUsers.add(friend);
        // TODO Add to database
        return true;
      }
      return false;
  
negative.code:               barrierDismissible: false);
            get(CodeWarsAPI.getUser(_user.username))
              ..then((val) {
                _performChangeUser(val.body);
                SharedPreferences.getInstance().then((sp) {
                  sp.setString(DatabaseKeys.USER, val.body);
                });
  