anchor.diff:  }
   
   /**
  - * Used to mark scope exit.
  + * Used to mark scope exit. [scope] is the return value of a call to [enter].
    */
  -dynamic leave(scope) {
  +void leave(scope) {
     if (wtfEnabled) {
       _arg1[0] = scope;
       _leaveScope.apply(_arg1, thisArg: _trace);
  
positive.code: }
  
  /**
   * Used to mark scope entry.
   *
   *     final myScope = createScope('myMethod');
   *
  
negative.code: }
  
  /**
   * Used to mark scope entry which logs single argument. The return value is used
   * to leave the scope again. Arguments only work if WTF has been enabled.
   */
  dynamic enter1(scope, arg1) {
    if (wtfEnabled) {
  