private void BindDropDown()
{
if (!string.IsNullOrWhiteSpace(GetAttributeValue("GroupTypes")))
{
var groupTypeService = new GroupTypeService(new RockContext());
List <String> groupTypeGuids = GetAttributeValue("GroupTypes").Split(',').ToList();
List <int> groupTypeIds = groupTypeService.GetListByGuids(groupTypeGuids.Select(Guid.Parse).ToList()).Select(gt => gt.Id).ToList();
gpGroups.IncludedGroupTypeIds = groupTypeIds;
}
}