### Question:
PendingTransactionDroppedSubscriptionService implements PendingTransactionDroppedListener { @Override public void onTransactionDropped(final Transaction transaction) { notifySubscribers(transaction.getHash()); } PendingTransactionDroppedSubscriptionService(
      final SubscriptionManager subscriptionManager); @Override void onTransactionDropped(final Transaction transaction);  }### Answer:
@Test public void onTransactionAddedMustSendMessage() { final long[] subscriptionIds = new long[] {5, 56, 989}; setUpSubscriptions(subscriptionIds); final Transaction pending = transaction(TX_ONE); service.onTransactionDropped(pending); verifyZeroInteractions(block); verifyZeroInteractions(blockchain); verifySubscriptionMangerInteractions(messages(TX_ONE, subscriptionIds)); }