anchor.diff:  
     dart$Callable([$dart$core.Function this._function, $dart$core.int this._variadicIndex = -1]);
   
  -  // for non-spread calls
  +  // for non-spread calls `f()`
     $dart$core.Function get f => _variadicIndex == -1 ? _function : this;
   
  -  // for spread calls, always use noSuchMethod.
  -  //$dart$core.Function get s => this;
  +  // for spread calls `s()`, always use noSuchMethod.
   
     noSuchMethod($dart$core.Invocation invocation) {
       if (invocation.memberName == #call) {
  
positive.code: 
  abstract
  class Callable {
      $dart$core.Function f;
      $dart$core.Function s;
  }
  
  //
  
negative.code:           outArgs[_variadicIndex]
                = new Tuple.$withList(inArgs.sublist(initialLength, inArgs.length - 1), seq);
          }
  
          return $dart$core.Function.apply(_function, outArgs, null);
        }
      }
  