/**
  * Main Condo_Properties_Settings Instance
  *
  * Ensures only one instance of Condo_Properties_Settings is loaded or can be loaded.
  *
  * @since 1.0.0
  * @static
  * @see Condo_Properties()
  * @return Main Condo_Properties_Settings instance
  */
 public static function instance($parent)
 {
     if (is_null(self::$_instance)) {
         self::$_instance = new self($parent);
     }
     return self::$_instance;
 }