/**
  * Convert the class to data-* attribute friendly associative array
  * will become data-key="value"
  * Exclude values if default
  *
  * @return array associative array
  */
 public function toHTMLDataArray()
 {
     $data = parent::toHTMLDataArray();
     if (isset($this->recommendations) && $this->recommendations === true) {
         $data['recommendations'] = 'true';
     }
     if (isset($this->filter)) {
         $data['filter'] = $this->filter;
     }
     return $data;
 }