docs: private Set<String> getRelatedElementIds(String id) {
  
          Set<String> result = new HashSet<String>();
          if (id != null) {
              result.add(id);
              String serverId = getServerId(id);
  
              Iterator<String> it = m_elements.keySet().iterator();
              while (it.hasNext()) {
                  String elId = it.next();
                  if (elId.startsWith(serverId)) {
                      result.add(elId);
                  }
              }
  
              Iterator<org.opencms.ade.containerpage.client.ui.CmsContainerPageElementPanel> itEl = getAllDragElements().iterator();
              while (itEl.hasNext()) {
                  org.opencms.ade.containerpage.client.ui.CmsContainerPageElementPanel element = itEl.next();
                  if (element.getId().startsWith(serverId)) {
                      result.add(element.getId());
                  }
              }
          }
          return result;
      }