docs: @Nonnull
    @ReturnsMutableCopy
    public ICommonsList <String> getAllUserGroupIDsWithAssignedRole (@Nullable final String sRoleID)
    {
      if (StringHelper.hasNoText (sRoleID))
        return getNone ();
  
      return getAllMapped (aUserGroup -> aUserGroup.containsRoleID (sRoleID), IUserGroup::getID);
    }