Issue #2658628 by tim.plunkett:...

Issue #2658628 by tim.plunkett: \Drupal\Core\Entity\EntityWithPluginCollectionInterface has no reason to be entity specific

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

@@ -7,6 +7,8 @@
 
 namespace Drupal\Core\Entity;
 
+use Drupal\Core\Plugin\ObjectWithPluginCollectionInterface;
+
 /**
  * Provides an interface for an object using a plugin collection.
  *
@@ -14,15 +16,6 @@
  *
  * @ingroup plugin_api
  */
-interface EntityWithPluginCollectionInterface extends EntityInterface {
-
-  /**
-   * Gets the plugin collections used by this entity.
-   *
-   * @return \Drupal\Component\Plugin\LazyPluginCollection[]
-   *   An array of plugin collections, keyed by the property name they use to
-   *   store their configuration.
-   */
-  public function getPluginCollections();
+interface EntityWithPluginCollectionInterface extends EntityInterface, ObjectWithPluginCollectionInterface {
 
 }

core/lib/Drupal/Core/Plugin/ObjectWithPluginCollectionInterface.php

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Plugin\ObjectWithPluginCollectionInterface.
+ */
+
+namespace Drupal\Core\Plugin;
+
+/**
+ * Provides an interface for an object using a plugin collection.
+ *
+ * @see \Drupal\Component\Plugin\LazyPluginCollection
+ *
+ * @ingroup plugin_api
+ *
+ * Entities that need this interface should implement
+ * \Drupal\Core\Entity\EntityWithPluginCollectionInterface, which extends this.
+ */
+interface ObjectWithPluginCollectionInterface {
+
+  /**
+   * Gets the plugin collections used by this entity.
+   *
+   * @return \Drupal\Component\Plugin\LazyPluginCollection[]
+   *   An array of plugin collections, keyed by the property name they use to
+   *   store their configuration.
+   */
+  public function getPluginCollections();
+
+}