code: public void createSubSitemap(final CmsUUID entryId) {
  
          CmsRpcAction<CmsSitemapChange> subSitemapAction = new CmsRpcAction<CmsSitemapChange>() {
  
              /**
               * @see org.opencms.gwt.client.rpc.CmsRpcAction#execute()
               */
              @Override
              public void execute() {
  
                  start(0, true);
                  getService().createSubSitemap(entryId, this);
              }
  
              /**
               * @see org.opencms.gwt.client.rpc.CmsRpcAction#onResponse(java.lang.Object)
               */
              @Override
              protected void onResponse(CmsSitemapChange result) {
  
                  stop(false);
                  applyChange(result);
              }
          };
          subSitemapAction.execute();
      }
docs: Creates a sub-sitemap from the subtree of the current sitemap starting at the given entry.<p>
  
  @param entryId the id of the entry