@Test
public void testTriggerVertex() {

  final MessageAggregatorVertex maOne = insertNewTriggerVertex(irdag, oneToOneEdge);
  mustPass();
  final MessageAggregatorVertex maTwo = insertNewTriggerVertex(irdag, shuffleEdge);
  mustPass();
  irdag.delete(maTwo);
  mustPass();
  irdag.delete(maOne);
  mustPass();
}