code: function createWechat (elem, data) {
          var wechat = getElementsByClassName(elem, 'icon-wechat', 'a');
  
          if (wechat.length === 0) {
              return false;
          }
  
          var elems = createElementByString('<div class="wechat-qrcode"><h4>' + data.wechatQrcodeTitle + '</h4><div class="qrcode"></div><div class="help">' + data.wechatQrcodeHelper + '</div></div>');
          var qrcode = getElementsByClassName(elems[0], 'qrcode', 'div');
  
          new QRCode(qrcode[0], {text: data.url, width: data.wechatQrcodeSize, height: data.wechatQrcodeSize});
          wechat[0].appendChild(elems[0]);
      }
docs: Create the wechat icon and QRCode.
  
  @param {Element} elem
  @param {Object} data