public static @Nullable NotificationParentGroupBean findParent(@NotNull NotificationSettings setting) {
    prepareInfo();

    String groupId = setting.getGroupId();
    NotificationGroup group = NotificationGroup.findRegisteredGroup(groupId);
    NotificationParentGroupBean parent;

    if (group == null) {
      parent = myGroupToParent.get(groupId);
    }
    else {
      String parentId = group.getParentId();
      if (parentId == null) {
        parent = myGroupToParent.get(group.getDisplayId());
        if (parent != null) {
          group.setParentId(parent.id);
        }
      }
      else {
        parent = myParents.get(parentId);
      }
    }

    return parent;
  }
public static @Nullable NotificationParentGroupBean findParent(@NotNull NotificationSettings setting)