private VersionDefinitionXml timedVDFLoad(URI uri) throws Exception {
    long time = System.currentTimeMillis();

    try {
      return VersionDefinitionXml.load(uri.toURL());
    } finally {
      LOG.debug("Loaded VDF {} in {}ms", uri, System.currentTimeMillis() - time);
    }

  }
Merges definitions loaded from the common file
@param stackId the stack id
@param version the version string
@param osMap   the map containing all the VDF for an OS
@return the merged version definition
@throws Exception
ambari-server/src/main/java/org/apache/ambari/server/state/stack/RepoVdfCallable.java