code: function(variant){
      variant = variant ? (' for ' + variant) : '';
      var info = '/**\n';
      info += ' * ' + pkg.name + ' ' + pkg.version + variant + '\n';
      info += ' * Copyright 2016 alibaba.com\n';
      info += ' * Licensed under the MIT License\n';
      info += ' */\n';
      return info;
  }
docs: format