/**
  * Returns the icon URL from the parameter value.
  * 
  * @param  AbstractContent $content   The content.
  * @param  string          $paramName The parameter name.
  * 
  * @return string|null                The icon URL.
  */
 private function iconizeByParam(AbstractContent $content, $paramName)
 {
     if (null === ($parameter = $content->getParam($paramName))) {
         return null;
     }
     if (empty($parameter['value'])) {
         return null;
     }
     return $parameter['value'];
 }
 /**
  * Returns defined parameters.
  *
  * @param string $key The parameter to be return, if NULL, all parameters are returned
  *
  * @return mixed the parameter value or NULL if unfound
  */
 public function getParam($key)
 {
     return null !== $this->getDraft() ? $this->getDraft()->getParam($key) : parent::getParam($key);
 }