code: public List<String> getSubItems() {
  
          if (isGroupContainer()) {
              return m_subItems;
          } else if (isInheritContainer()) {
              List<String> result = new ArrayList<String>();
              for (CmsInheritanceInfo info : m_inheritanceInfos) {
                  if (info.isVisible()) {
                      result.add(info.getClientId());
                  }
              }
              return result;
          } else {
              throw new UnsupportedOperationException("Only group or inherit containers have sub-items");
          }
      }
docs: Returns the sub-items.<p>
  
  @return the sub-items