Issue #2089485 by smiletrl: [follow-up]: Clean up for file field type.

core/modules/file/lib/Drupal/file/Plugin/field/field_type/FileItem.php

@@ -47,16 +47,6 @@ class FileItem extends EntityReferenceItem implements ConfigFieldItemInterface {
    */
   static $propertyDefinitions;
 
-  /**
-   * {@inheritdoc}
-   */
-  public function getInstance() {
-    if (!isset($this->instance) && $parent = $this->getParent()) {
-      $this->instance = $parent->getInstance();
-    }
-    return $this->instance;
-  }
-
   /**
    * {@inheritdoc}
    */