public synchronized void start(){
  if (expirationTime == -1) {
    expired=false;
    expirationTime=LIFETIME + System.currentTimeMillis();
  }
 else {
    throw new IllegalStateException("StunServerTransaction " + getTransactionID() + " has already been started!");
  }
}

public synchronized void start ( ) { if ( expirationTime == - 1 ) { expired = false ; expirationTime = LIFETIME + System . currentTimeMillis ( ) ; } else { throw new IllegalStateException ( "StunServerTransaction " + getTransactionID ( ) + " has already been started!" ) ; } }
start the transaction . this launches the countdown to the moment the transaction would expire .
