Наследование: extends Singleton
 /**
  * Internal events should be scheduled
  */
 function test_events()
 {
     \Automattic\WP\Cron_Control\Internal_Events::instance()->schedule_internal_events();
     $events = \Automattic\WP\Cron_Control\collapse_events_array(get_option('cron'));
     // Check that the plugin scheduled the expected number of events
     $this->assertEquals(count($events), 4);
     // Confirm that the scheduled jobs came from the Internal Events class
     foreach ($events as $event) {
         $this->assertTrue(\Automattic\WP\Cron_Control\is_internal_event($event['action']));
     }
 }