gistfile1.php

class Ai1ec_Event_Dispatcher {

    public function register(
        $hook,
        Ai1ec_Event_Callback_Abstract $entity,
        $priority = 10,
        $accepted_args = 1
    ) {

		if ($entity instanceof Ai1ec_Event_Callback_Filter) {
			add_filter(
				$hook,
				array( $entity, $entity->getMethod() ),
				$priority,
				$accepted_args
			);
		} else {
			add_action(
				$hook,
				array( $entity, $entity->getMethod() ),
				$priority,
				$accepted_args
			);		
		}

        return $this;
    }
}