code: function(key) {
      var strCss = '';
      strCss += '@' + (typeof key.vendor !== 'undefined' ? key.vendor : '') + 'keyframes ' + key.name + ' {\n\n';
      key.keyframes.forEach(function(keyframe) {
        strCss += commentOrKeyframe(keyframe);
      });
      strCss += '}\n\n';
  
      return strCss;
    }
docs: Process keyframes