code: function(pseudoRule, element, elementTagName){
          if(pseudoRule.name === 'checked'){
              return this.checked(element, elementTagName);
          }
          if(pseudoRule.name === 'empty'){
              return this.empty(element);
          }
      }
docs: Routes pseudo selector to proper handler
  @param  {Object} pseudoRule     Parsed CSS pseudo rule
  @param  {Object} element        Element to check against pseudo rule
  @param  {String} elementTagName Tag name of the element
  @return {Bool}                  Whether element matches pseudo rule