anchor.diff:  void _call(initPort) {
     initPort.send(singleMessagePort(callFunc));
   }
  -  // Expect.throws(() {
  -  //   noReply.sendPort.send([func]);
  -  // }, null, "send wrapped");
  -
   
   void testUnsendable(name, func) {
     asyncStart();
  
positive.code:   // Sendables are top-level functions and static functions only.
    testSendable("toplevel", toplevel);
    testSendable("static", C.staticFunc);
  
    // Unsendables are any closure - instance methods or function expression.
    var c = new C();
    testUnsendable("instance method", c.instanceMethod);
  
negative.code:   // not a top-level or static function, so it should be blocked, just as
    // a normal method.
    testUnsendable("callable object", new Callable().call);
  
    asyncEnd();
    return;
  }
  