woothemes/woocommerce — pull request #5681 by artevio (2014-06-16 19:41:22+00:00)
Title: class-wc-coupon.php

Is it possible to modify lines in your class-wc-coupon.php like this?

My plugin for WooCommerce adds new coupon types and I need to have a possibility to hook validation check for my newly added coupon types. Because if they will not get validated I can't calculate them.

Please help me with this.