code: function(src, opt, callback) {
    if (Object.prototype.toString.call(src) !== '[object String]')
      throw new TypeError('First parameter must be a string.');
    src = src.trim();
    var mySplitInput = splitInput(src);
  
    return mySplitInput ?  {
        meta : yaml.safeLoad(mySplitInput[0]),
        html : marked(mySplitInput[1], opt, callback)
      } : {
        meta : null,
        html : marked(src, opt, callback)
      };
  }
docs: [Based on meta-marked](https://github.com/j201/meta-marked)