private void AddMapDefinition(string resId, string prefix)
        {
            int    counter = 0;
            string name    = prefix;

            while (_flexLayout.MapSet.GetGroupById(name) != null)
            {
                counter++;
                name = prefix + counter;
            }

            var grp = _flexLayout.AddMapGroup(name, true, resId);

            OnResourceChanged();
            AddMap(grp);
        }