docs: public void save(CmsObject cms, CmsContainerPageBean cntPage, boolean ifChangedOnly) throws CmsException {
  
          CmsFile file = getFile();
          byte[] data = createContainerPageXml(cms, cntPage);
          if (ifChangedOnly && Arrays.equals(file.getContents(), data)) {
              return;
          }
          // lock the file
          cms.lockResourceTemporary(file);
          file.setContents(data);
          cms.writeFile(file);
      }