@Override
public long renewDelegationToken(Token<DelegationTokenIdentifier> t)
throws InvalidToken, IOException {
MyToken token = (MyToken)t;
if(token.isCanceled()) {
throw new InvalidToken("token has been canceled");
}
counter ++;
this.token = (MyToken)token;
System.out.println("Called MYDFS.renewdelegationtoken " + token +
";this dfs=" + this.hashCode() + ";c=" + counter);