code: function(element, tagName){
          if(!tagName || tagName.toLowerCase() !== 'input'){
              return false;
          }
  
          var inputType = element.type.toLowerCase();
          if(inputType !== 'checkbox' && inputType !== 'radio'){
              return false;
          }
  
          return element.checked !== false;
      }
docs: Checks if the provided element is "checked". Only applies to inputs of type radio
  and checkbox. Checks for both the checked property and defaultChecked property.
  @param  {Object} element Element to test
  @param  {String} tagName Tag name of the element
  @return {Bool}           Whether element is the correct input type and is checked