code: function(css,retinaobject,properties){
          var _tmpSlice = retinaobject.slicekey;
          var _retinaCSSCode = "";
          var _sprite ;
              _retinaCSSCode +='\n\n@media only screen and (-webkit-min-device-pixel-ratio: 1.5),only screen and (min--moz-device-pixel-ratio: 1.5),only screen and (min-resolution: 240dpi){';
              for(var key in _tmpSlice){
                  _sprite = _tmpSlice[key].code;
                  _retinaCSSCode += _tmpSlice[key].className;
                  _retinaCSSCode += "{background-image:url(.";
                  _retinaCSSCode += _outSpritePath.slice(_outSpritePath.lastIndexOf("/"),_outSpritePath.length);
                  _retinaCSSCode += "/";
                  _retinaCSSCode += _outSpriteName.replace(".png","@2x.png")+");";
                  _retinaCSSCode += "background-position: -";
                  _retinaCSSCode += (_sprite.x) / 2;
                  _retinaCSSCode += "px -";
                  _retinaCSSCode += (_sprite.y) / 2;
                  _retinaCSSCode += "px;background-size:";
                  _retinaCSSCode += (properties.width) / 2 + 'px;}';
              }
              _retinaCSSCode += '\n}\n';
          css = css + _retinaCSSCode;
          return css;
      }
docs: [_updateRetinaStyleHandler 更新retina样式支持]
  @param  {[string]} css          [增加过的普通雪碧图的样式]
  @param  {[object]} retinaobject [retina相关的样式雪碧图]
  @param  {[object]} properties   [雪碧图的信息]
  @return {[string]}              [返回增加后的样式]