Issue #3260520 by TR: GenericEvent is used improperly

core/lib/Drupal/Core/Entity/EntityTypeEvent.php

@@ -2,12 +2,12 @@
 
 namespace Drupal\Core\Entity;
 
-use Symfony\Component\EventDispatcher\GenericEvent;
+use Drupal\Component\EventDispatcher\Event;
 
 /**
  * Defines a base class for all entity type events.
  */
-class EntityTypeEvent extends GenericEvent {
+class EntityTypeEvent extends Event {
 
   /**
    * The entity type.

core/lib/Drupal/Core/Field/FieldStorageDefinitionEvent.php

@@ -2,12 +2,12 @@
 
 namespace Drupal\Core\Field;
 
-use Symfony\Component\EventDispatcher\GenericEvent;
+use Drupal\Component\EventDispatcher\Event;
 
 /**
  * Defines a base class for all field storage definition events.
  */
-class FieldStorageDefinitionEvent extends GenericEvent {
+class FieldStorageDefinitionEvent extends Event {
 
   /**
    * The field storage definition.