anchor.diff:  
       return false;
     }
  -
  -  bool operator ==(other) {
  -    if (other is !TypedSelector) return false;
  -    if (other.receiverType !== receiverType) return false;
  -    return super == other;
  -  }
   }
  
positive.code:   int hashCode() => argumentCount + 1000 * namedArguments.length;
    int get namedArgumentCount() => namedArguments.length;
    int get positionalArgumentCount() => argumentCount - namedArgumentCount;
  
    static final Selector GETTER =
        const Selector.constant(SelectorKind.GETTER, 0);
  
negative.code:   }
  
    bool operator ==(other) {
      if (other is !Selector) return false;
      if (receiverType !== other.receiverType) return false;
      return argumentCount == other.argumentCount
             && namedArguments.length == other.namedArguments.length
             && sameNames(namedArguments, other.namedArguments);
  