public Transaction seen(Transaction tx,PeerAddress byPeer){
  lock.lock();
  try {
    final Transaction interned=intern(tx);
    markBroadcast(byPeer,interned);
    return interned;
  }
  finally {
    lock.unlock();
  }
}

public Transaction seen ( Transaction tx , PeerAddress byPeer ) { lock . lock ( ) ; try { final Transaction interned = intern ( tx ) ; markBroadcast ( byPeer , interned ) ; return interned ; } finally { lock . unlock ( ) ; } }
called by peers when they receive a " tx " message containing a valid serialized transaction .
