source: class IRDAGTest {
  
    private static final Logger LOG;
    private final static int MIN_THREE_SOURCE_READABLES;
    private SourceVertex sourceVertex;
    private IREdge oneToOneEdge;
    private OperatorVertex firstOperatorVertex;
    private IREdge shuffleEdge;
    private OperatorVertex secondOperatorVertex;
    private IRDAG irdag;
    private Random random;
  
    @Test
    public void testSignalVertex() {
  
target:     final SignalVertex sg1 = insertNewSignalVertex(irdag, oneToOneEdge);
      mustPass();
  
      final SignalVertex sg2 = insertNewSignalVertex(irdag, shuffleEdge);
      mustPass();
  
      irdag.delete(sg1);
      mustPass();
  
      irdag.delete(sg2);
      mustPass();
    }
  
  }