Do not keep track of slots on drawer

cache_register.services.yml

 services:
   cache_register.manager:
     class: Drupal\cache_register\Manager
-    arguments: [ '@cache.data' ]
+    arguments: [ '@cache', '@cache.data' ]
 
   #
   # Not really sure if there's a benefit to doing this,

src/Drawer.php

@@ -20,13 +20,6 @@ class Drawer implements DrawerInterface {
    */
   protected $id;
 
-  /**
-   * Array of slots in the drawer.
-   *
-   * @var Slot[]
-   */
-  protected $slots = [];
-
   /**
    * The constructor.
    *
@@ -48,9 +41,7 @@ class Drawer implements DrawerInterface {
    * {@inheritDoc}
    */
   public function createSlot($slot_ids) {
-    $slot = new Slot($this->cache, $this, $slot_ids);
-    $this->slots[] = $slot;
-    return $slot;
+    return new Slot($this->cache, $this, $slot_ids);
   }
 
   /**
@@ -60,22 +51,6 @@ class Drawer implements DrawerInterface {
     return $this->id;
   }
 
-  /**
-   * {@inheritDoc}
-   */
-  public function getSlots() {
-    return $this->slots;
-  }
-
-  /**
-   * {@inheritDoc}
-   */
-  public function deleteAll() {
-    foreach ($this->slots as $slot) {
-      $slot->deleteCache();
-    }
-  }
-
   /**
    * {@inheritDoc}
    */

src/DrawerInterface.php

@@ -29,19 +29,7 @@ interface DrawerInterface {
   public function id();
 
   /**
-   * @return \Drupal\cache_register\SlotInterface[]
-   */
-  public function getSlots();
-
-  /**
-   * Invalidate (delete) all child slot cache entries.
-   *
-   * @return mixed
-   */
-  public function deleteAll();
-
-  /**
-   * Invalidate (delete) all child slot cache entries.
+   * Invalidate all slots in the drawer.
    *
    * @return mixed
    */