@Override
public long renew(Token<?> t, Configuration conf) throws IOException {
MyToken token = (MyToken)t;
if(token.isCanceled()) {
throw new InvalidToken("token has been canceled");
}
lastRenewed = token;
counter ++;
LOG.info("Called MYDFS.renewdelegationtoken " + token +
";this dfs=" + this.hashCode() + ";c=" + counter);