code: function (elm, name, value) {
          var self = this, originalValue, hook, settings = self.settings;
  
          if (value === '') {
            value = null;
          }
  
          elm = self.$$(elm);
          originalValue = elm.attr(name);
  
          if (!elm.length) {
            return;
          }
  
          hook = self.attrHooks[name];
          if (hook && hook.set) {
            hook.set(elm, value, name);
          } else {
            elm.attr(name, value);
          }
  
          if (originalValue != value && settings.onSetAttrib) {
            settings.onSetAttrib({
              attrElm: elm,
              attrName: name,
              attrValue: value
            });
          }
        }
docs: Sets the specified attribute of an element or elements.
  
  @method setAttrib
  @param {Element/String/Array} elm DOM element, element id string or array of elements/ids to set attribute on.
  @param {String} name Name of attribute to set.
  @param {String} value Value to set on the attribute - if this value is falsy like null, 0 or '' it will remove
  the attribute instead.
  @example
  // Sets class attribute on all paragraphs in the active editor
  tinymce.activeEditor.dom.setAttrib(tinymce.activeEditor.dom.select('p'), 'class', 'myclass');
  
  // Sets class attribute on a specific element in the current page
  tinymce.dom.setAttrib('mydiv', 'class', 'myclass');