code: public CmsExtractionResult getCacheObject(String rfsName) {
  
          try {
              File f = new File(rfsName);
              if (f.exists()) {
                  long age = f.lastModified();
                  if ((System.currentTimeMillis() - age) > 3600000) {
                      // file has not been touched for 1 hour, touch the file with the current date
                      f.setLastModified(System.currentTimeMillis());
                  }
                  byte[] byteContent = CmsFileUtil.readFile(f);
                  return CmsExtractionResult.fromBytes(byteContent);
              }
          } catch (IOException e) {
              // unable to read content
          }
          // this code can be reached only in case of an error
          return null;
      }
docs: Returns the extraction result in the requested file in the disk cache, or <code>null</code> if the
  file is not found in the cache, or is found but out-dated.<p>
  
  @param rfsName the file RFS name to look up in the cache
  
  @return the extraction result stored in the requested file in the RFS disk cache, or <code>null</code>