public String getDelegationToken(String owner, String renewer)
    throws HiveException{
    try {
      return getMSC().getDelegationToken(owner, renewer);
    } catch(Exception e) {
      LOG.error("Failed getDelegationToken", e);
      throw new HiveException(e);
    }
  }
@return the metastore client for the current thread
@throws MetaException
ql/src/java/org/apache/hadoop/hive/ql/metadata/Hive.java