code: public static CmsXmlContainerPage unmarshal(CmsObject cms, CmsResource resource) throws CmsException {
  
          // check the cache
          CmsXmlContainerPage content = getCache(cms, resource, true);
          if (content != null) {
              return content;
          }
  
          content = unmarshal(cms, cms.readFile(resource), true);
  
          // set the cache
          setCache(cms, content, true);
  
          return content;
      }
docs: Factory method to unmarshal (read) a container page instance from a OpenCms VFS resource
  that contains XML data.<p>
  
  <b>Warning:</b><br/>
  This method does not support requested historic versions, it always loads the
  most recent version. Use <code>{@link #unmarshal(CmsObject, CmsResource, ServletRequest)}</code>
  for history support.<p>
  
  @param cms the current cms object
  @param resource the resource with the XML data to unmarshal
  
  @return a container page instance unmarshalled from the provided resource
  
  @throws CmsException if something goes wrong