/**
  * Returns and/or create the single instance of this class.  
  *
  * @return  Charitable_Donation_Processor
  * @access  public
  * @since   1.0.0
  */
 public static function get_instance()
 {
     if (is_null(self::$instance)) {
         self::$instance = new Charitable_Donation_Processor();
     }
     return self::$instance;
 }
 /**
  * Destroy the Charitable_Donation_Processor instance.
  *
  * This is primarily useful for testing purposes, as it allows you to
  * create multiple donations in a single request.
  *
  * @return  void
  * @access  public
  * @static
  * @since   1.3.0
  */
 public static function destroy()
 {
     self::$instance = null;
 }