code: public List<CmsOrganizationalUnit> getOrganizationalUnits(CmsObject cms, String ouFqn, boolean includeChildren)
      throws CmsException {
  
          CmsOrganizationalUnit parent = readOrganizationalUnit(cms, ouFqn);
          return m_securityManager.getOrganizationalUnits(cms.getRequestContext(), parent, includeChildren);
      }
docs: Returns all child organizational units of the given parent organizational unit including
  hierarchical deeper organization units if needed.<p>
  
  @param cms the opencms context
  @param ouFqn the fully qualified name of the parent organizational unit
  @param includeChildren if hierarchical deeper organization units should also be returned
  
  @return a list of <code>{@link CmsOrganizationalUnit}</code> objects
  
  @throws CmsException if operation was not successful