gistfile1.php

<?php
class My_Gateway implements APP_Instant_Payment_Processor, APP_Recurring_Payment_Processor { 
 
  public function process( APP_Instant_Order $order, array $options ) {
    // ... processing instructions
  }
  
  public function form() {
    // ... return form fields
  }

  public function process_recurring( APP_Instant_Order $order, array $options ) {
    // ... processing recurring transaction
  }
  
}