diff --git a/core/modules/rest/src/Tests/RESTFileValidationTest.php b/core/modules/rest/src/Tests/RESTFileValidationTest.php
index d5507db..2a3f013 100644
--- a/core/modules/rest/src/Tests/RESTFileValidationTest.php
+++ b/core/modules/rest/src/Tests/RESTFileValidationTest.php
@@ -11,6 +11,7 @@
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\field\Entity\FieldConfig;
 use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\file\Entity\File;
 use Drupal\node\Entity\Node;
 use Drupal\user\RoleInterface;
 
@@ -59,22 +60,29 @@ public function testCreateNodeWithFile() {
     user_role_grant_permissions(RoleInterface::ANONYMOUS_ID, $permissions);
 
     // Create a private file and attach it to a node.
-    $this->createFileField('field_private_file', 'node', 'resttest', ['uri_scheme' => 'private'], ['file_extensions' => 'txt']);
-    $permissions = ['create resttest content'];
-    $account = $this->drupalCreateUser($permissions);
-    $this->drupalLogin($account);
-
+    $this->createFileField('field_private_file', 'node', 'page', ['uri_scheme' => 'private'], ['file_extensions' => 'txt']);
     $private_files = $this->drupalGetTestFiles('text', NULL, FALSE);
-    $edit = [
-      'title[0][value]' => 'Test private title',
-      'files[field_private_file_0]' => drupal_realpath($private_files[0]->uri),
-    ];
-    $this->drupalPostForm('node/add/resttest', $edit, t('Save'));
-    preg_match('@node/(\d+)@', $this->getUrl(), $matches);
-    $nid = $matches[1];
-    $node = Node::load($nid);
-    $this->drupalLogout();
+    $private_file_author = $this->drupalCreateUser([]);
+    $file = File::create([
+      'uri' => $private_files[0]->uri,
+    ]);
+    $file->save();
+    $node = Node::create([
+      'title' => 'Test private title',
+      'type' => 'page',
+      'uid' => $private_file_author->id(),
+      'field_private_file' => [
+        0 => [
+          'target_id' => $file->id(),
+        ],
+      ],
+    ]);
+    $node->save();
 
+    $this->drupalLogin($private_file_author);
+    $this->drupalGet(file_create_url($private_files[0]->uri));
+    $this->assertResponse(200);
+    $this->drupalLogout();
     $this->drupalGet(file_create_url($private_files[0]->uri));
     $this->assertResponse(403);
 
@@ -88,6 +96,7 @@ public function testCreateNodeWithFile() {
     // Verify that user cannot create content when trying to write to fields
     // where it is not possible.
 
+    $account = \Drupal::currentUser();
     $serialized = $this->serializer->serialize($entity, $this->defaultFormat, ['account' => $account]);
     $this->httpRequest('entity/node', 'POST', $serialized, $this->defaultMimeType);
     $this->assertResponse(403);
@@ -126,7 +135,7 @@ public function testCreateNodeWithFile() {
    *
    * @return \Drupal\Core\Entity\EntityInterface
    */
-  function createFileField($name, $entity_type, $bundle, $storage_settings = [], $field_settings = [], $widget_settings = []) {
+  protected function createFileField($name, $entity_type, $bundle, $storage_settings = [], $field_settings = [], $widget_settings = []) {
     $field_storage = FieldStorageConfig::create([
       'entity_type' => $entity_type,
       'field_name' => $name,
@@ -154,7 +163,7 @@ function createFileField($name, $entity_type, $bundle, $storage_settings = [], $
    * @param array $widget_settings
    *   A list of widget settings that will be added to the widget defaults.
    */
-  function attachFileField($name, $entity_type, $bundle, $field_settings = [], $widget_settings = []) {
+  protected function attachFileField($name, $entity_type, $bundle, $field_settings = [], $widget_settings = []) {
     FieldConfig::create([
       'field_name' => $name,
       'label' => $name,
@@ -179,115 +188,4 @@ function attachFileField($name, $entity_type, $bundle, $field_settings = [], $wi
       ->save();
   }
 
-  /**
-   * Creates the entity over the REST API.
-   *
-   * @param string $entity_type
-   *   The type of the entity that should be created.
-   * @param string $serialized
-   *   The body for the POST request.
-   */
-  public function assertCreateEntityOverRestApi($entity_type, $serialized = NULL) {
-    // Note: this will fail with PHP 5.6 when always_populate_raw_post_data is
-    // set to something other than -1. See https://www.drupal.org/node/2456025.
-    $this->httpRequest('entity/' . $entity_type, 'POST', $serialized, $this->defaultMimeType);
-    $this->assertResponse(201);
-  }
-
-  /**
-   * Gets the new entity ID from the location header and tries to read it from
-   * the database.
-   *
-   * @param string $entity_type
-   *   Entity type we need to load the entity from DB.
-   * @param \Drupal\Core\Entity\EntityInterface $entity
-   *   The entity we want to check that was inserted correctly.
-   * @param array $entity_values
-   *   The values of $entity.
-   */
-  public function assertReadEntityIdFromHeaderAndDb($entity_type, EntityInterface $entity, array $entity_values = array()) {
-    // Get the location from the HTTP response header.
-    $location_url = $this->drupalGetHeader('location');
-    $url_parts = explode('/', $location_url);
-    $id = end($url_parts);
-
-    // Get the entity using the ID found.
-    $loaded_entity = \Drupal::entityManager()->getStorage($entity_type)->load($id);
-    $this->assertNotIdentical(FALSE, $loaded_entity, 'The new ' . $entity_type . ' was found in the database.');
-    $this->assertEqual($entity->uuid(), $loaded_entity->uuid(), 'UUID of created entity is correct.');
-
-    // Verify that the field values sent and received from DB are the same.
-    foreach ($entity_values as $property => $value) {
-      $actual_value = $loaded_entity->get($property)->value;
-      $send_value = $entity->get($property)->value;
-      $this->assertEqual($send_value, $actual_value, 'Created property ' . $property . ' expected: ' . $send_value . ', actual: ' . $actual_value);
-    }
-
-    // Delete the entity loaded from DB.
-    $loaded_entity->delete();
-  }
-
-  /**
-   * Try to send invalid data that cannot be correctly deserialized.
-   *
-   * @param string $entity_type
-   *   The type of the entity that should be created.
-   */
-  public function assertCreateEntityInvalidData($entity_type) {
-    $this->httpRequest('entity/' . $entity_type, 'POST', 'kaboom!', $this->defaultMimeType);
-    $this->assertResponse(400);
-  }
-
-  /**
-   * Try to send no data at all, which does not make sense on POST requests.
-   *
-   * @param string $entity_type
-   *   The type of the entity that should be created.
-   */
-  public function assertCreateEntityNoData($entity_type) {
-    $this->httpRequest('entity/' . $entity_type, 'POST', NULL, $this->defaultMimeType);
-    $this->assertResponse(400);
-  }
-
-  /**
-   * Send an invalid UUID to trigger the entity validation.
-   *
-   * @param \Drupal\Core\Entity\EntityInterface $entity
-   *   The entity we want to check that was inserted correctly.
-   * @param string $entity_type
-   *   The type of the entity that should be created.
-   * @param array $context
-   *   Options normalizers/encoders have access to.
-   */
-  public function assertCreateEntityInvalidSerialized(EntityInterface $entity, $entity_type, array $context = array()) {
-    // Add a UUID that is too long.
-    $entity->set('uuid', $this->randomMachineName(129));
-    $invalid_serialized = $this->serializer->serialize($entity, $this->defaultFormat, $context);
-
-    $response = $this->httpRequest('entity/' . $entity_type, 'POST', $invalid_serialized, $this->defaultMimeType);
-
-    // Unprocessable Entity as response.
-    $this->assertResponse(422);
-
-    // Verify that the text of the response is correct.
-    $error = Json::decode($response);
-    $this->assertEqual($error['error'], "Unprocessable Entity: validation failed.\nuuid.0.value: <em class=\"placeholder\">UUID</em>: may not be longer than 128 characters.\n");
-  }
-
-  /**
-   * Try to create an entity without proper permissions.
-   *
-   * @param string $entity_type
-   *   The type of the entity that should be created.
-   * @param string $serialized
-   *   The body for the POST request.
-   */
-  public function assertCreateEntityWithoutProperPermissions($entity_type, $serialized = NULL) {
-    $this->drupalLogout();
-    $this->httpRequest('entity/' . $entity_type, 'POST', $serialized, $this->defaultMimeType);
-    // Forbidden Error as response.
-    $this->assertResponse(403);
-    $this->assertFalse(\Drupal::entityManager()->getStorage($entity_type)->loadMultiple(), 'No entity has been created in the database.');
-  }
-
 }