anchor.diff:    @override
     void beginLabeledStatement(Token token, int labelCount) {
       debugEvent("beginLabeledStatement");
  -    List<Label> labels =
  -        new List<Label>.filled(labelCount, null, growable: true);
  +    List<Label> labels = new List<Label>(labelCount);
       popList(labelCount, labels);
       enterLocalScope(null, scope.createNestedLabelScope());
       LabelTarget target =
  
positive.code:     }
      List<KernelFormalParameterBuilder> parameters;
      if (count + optionalsCount > 0) {
        parameters = new List<KernelFormalParameterBuilder>.filled(
            count + optionalsCount, null,
            growable: true);
        popList(count, parameters);
        if (optionals != null) {
          parameters.setRange(count, count + optionalsCount, optionals);
  
negative.code:       value = symbolPartToString(part);
        push(forest.literalSymbolSingluar(value, hashToken, part));
      } else {
        List<Identifier> parts =
            popList(identifierCount, new List<Identifier>(identifierCount));
        value = symbolPartToString(parts.first);
        for (int i = 1; i < parts.length; i++) {
          value += ".${symbolPartToString(parts[i])}";
  