code: public void setParentGroup(String groupName, String parentGroupName) throws CmsException {
  
          m_securityManager.setParentGroup(m_context, groupName, parentGroupName);
      }
docs: Sets a new parent-group for an already existing group.<p>
  
  @param groupName the name of the group that should be updated
  @param parentGroupName the name of the parent group to set,
  or <code>null</code> if the parent
  group should be deleted.
  
  @throws CmsException  if operation was not successful