documentation/_event_2_observer_interface_8php_source.html

 <?php
 namespace Magento\Framework\Event;

 interface ObserverInterface
 {
     public function execute(Observer $observer);
 }
Magento\Framework\Event
Definition: Collection.php:12

Magento\Framework\Event\ObserverInterface
Definition: ObserverInterface.php:16

$observer
$observer
Definition: second_website_with_second_currency.php:38

Magento\Framework\Event\ObserverInterface\execute
execute(Observer $observer)

Magento\Framework\Event\Observer
Definition: Observer.php:14