code: public void upgradeContent(CmsObject cms) throws CmsException {
  
          if (m_content == null) {
              m_content = cms.readFile(m_resource).getContents();
          }
      }
docs: Loads the content of the encapsulated CmsResource and stores it within the
  CmsContentCheckResource. If the content is already existing, it is not loaded
  again.<p>
  
  @param cms the CmsObject
  @throws CmsException if loading of the content fails