code: public List<CmsSitemapTreeNodeData> getChildren(CmsSitemapTreeNodeData nodeData) {
  
          CmsClientSitemapEntry entry = nodeData.getClientEntry();
  
          List<CmsSitemapTreeNodeData> result = Lists.newArrayList();
  
          try {
              CmsVfsSitemapService svc = getSitemapService();
              CmsClientSitemapEntry ent = svc.getChildren(m_root.getRootPath(), entry.getId(), 1);
              for (CmsClientSitemapEntry subEnt : ent.getSubEntries()) {
                  if (subEnt.isInNavigation()
                      && ((subEnt.getDefaultFileId() != null) || subEnt.isNavigationLevelType())) {
                      try {
                          CmsUUID idToRead = subEnt.getId();
                          if (subEnt.getDefaultFileId() != null) {
                              idToRead = subEnt.getDefaultFileId();
                          }
                          Locale l1 = OpenCms.getLocaleManager().getDefaultLocale(
                              svc.getCmsObject(),
                              svc.getCmsObject().readResource(idToRead));
                          Locale l2 = OpenCms.getLocaleManager().getDefaultLocale(
                              svc.getCmsObject(),
                              svc.getCmsObject().readResource(ent.getId(), CmsResourceFilter.IGNORE_EXPIRATION));
                          if (!l1.equals(l2)) {
                              continue;
                          }
                      } catch (Exception e) {
                          LOG.error(e.getLocalizedMessage(), e);
                      }
  
                      CmsSitemapTreeNodeData data = new CmsSitemapTreeNodeData(
                          m_localeContext.getRootLocale(),
                          m_localeContext.getComparisonLocale());
                      if (m_foldersWithNoChildFolders.contains(subEnt.getId())) {
                          data.setHasNoChildren(true);
                      }
                      data.setClientEntry(subEnt);
                      try {
                          data.initialize(m_cms);
                          result.add(data);
                      } catch (Exception e) {
                          LOG.error(e.getLocalizedMessage());
                      }
                  }
              }
          } catch (CmsException e) {
              LOG.error(e.getLocalizedMessage(), e);
          } catch (CmsRpcException e) {
              LOG.error(e.getLocalizedMessage(), e);
  
          }
          return result;
      }
docs: Gets the node data for children of a given node.<p>
  
  @param nodeData the node whose children to get
  @return the children