code: function process(content, encoding, attrs, node) {
      if (typeof content === 'undefined') {
        console.error(
          colors.red('process() : Undefined "content" parameters.')
        );
        return '';
      }
      if (!encoding || encoding === 'original') {
        return content;
      }
      var items = encoding.split(/\s*,\s*/);
      if (items.length > 1) {
        items.forEach(function (item) {
          content = process(content, item, attrs, node);
        });
        return content;
      }
      var processor = getProcessor(encoding);
      if (!processor) {
        console.error(
          colors.red('The "%s" processor does not exist.'), encoding
        );
        return content;
      }
      return processor(content, attrs, instance, node);
    }
docs: 将内容进行编码
  
  @param {string} content 内容
  @param {string} encoding 编码名称
  @param {Object} attrs 属性集合
  @return {Function} 返回编码后的结果