/**
  * Overload get_option to optionally return a key within the returned option.
  */
 function get_option($key = false)
 {
     $option = parent::get_option();
     if (empty($key)) {
         return $option;
     }
     if (isset($option[$key])) {
         return $option[$key];
     }
     if (isset($this->default[$key])) {
         return $this->default[$key];
     }
     return false;
 }