docs: function _execCommand(doc, composer, command, nodeName, className) {
      var ranges = composer.selection.getOwnRanges();
      for (var i = ranges.length; i--;){
        composer.selection.getSelection().removeAllRanges();
        composer.selection.setSelection(ranges[i]);
        if (className) {
          var eventListener = dom.observe(doc, "DOMNodeInserted", function(event) {
            var target = event.target,
                displayStyle;
            if (target.nodeType !== wysihtml5.ELEMENT_NODE) {
              return;
            }
            displayStyle = dom.getStyle("display").from(target);
            if (displayStyle.substr(0, 6) !== "inline") {
              // Make sure that only block elements receive the given class
              target.className += " " + className;
            }
          });
        }
        doc.execCommand(command, false, nodeName);
  
        if (eventListener) {
          eventListener.stop();
        }
      }
    }