anchor.diff:  
   var afterCounter = 0;
   
  -@After(SomeService_sayHello)
  +someService_sayHello_noRetVal(component, Invocation inv, retVal) =>
  +    SomeService_sayHello(component, inv);
  +
  +@After(someService_sayHello_noRetVal)
   increaseAfterCounter(retVal) {
     afterCounter++;
     print("after sayHello $afterCounter");
  
positive.code: 
  var beforeCounter = 0;
  
  bool SomeService_sayHello(InstanceMirror im, Invocation inv) =>
      im.reflectee is SomeService
      && inv.memberName == #sayHello;
  
  @Before(SomeService_sayHello)
  
negative.code: 
  var afterTrhowingCounter = 0;
  
  SomeService_throwinError(component, Invocation inv, ex) =>
      ex is Exception
      && component is SomeService
      && inv.memberName == #throwsError;
  
  @AfterThrowing(SomeService_throwinError)
  increaseAfterThrowingCounter(retVal, Exception ex) {
    afterTrhowingCounter++;
    print("after throwing $afterTrhowingCounter");
    print(ex);
  