reverted:
--- b/core/modules/image/src/Tests/ImageFieldTestBase.php
+++ a/core/modules/image/src/Tests/ImageFieldTestBase.php
@@ -2,8 +2,9 @@
 
 namespace Drupal\image\Tests;
 
+use Drupal\field\Entity\FieldConfig;
-use Drupal\Tests\image\Kernel\ImageFieldCreationTrait;
 use Drupal\simpletest\WebTestBase;
+use Drupal\field\Entity\FieldStorageConfig;
 
 /**
  * TODO: Test the following functions.
@@ -23,8 +24,6 @@
  */
 abstract class ImageFieldTestBase extends WebTestBase {
 
-  use ImageFieldCreationTrait;
-
   /**
    * Modules to enable.
    *
@@ -53,6 +52,62 @@
   }
 
   /**
+   * Create a new image field.
+   *
+   * @param string $name
+   *   The name of the new field (all lowercase), exclude the "field_" prefix.
+   * @param string $type_name
+   *   The node type that this field will be added to.
+   * @param array $storage_settings
+   *   A list of field storage settings that will be added to the defaults.
+   * @param array $field_settings
+   *   A list of instance settings that will be added to the instance defaults.
+   * @param array $widget_settings
+   *   Widget settings to be added to the widget defaults.
+   * @param array $formatter_settings
+   *   Formatter settings to be added to the formatter defaults.
+   * @param string $description
+   *   A description for the field.
+   */
+  function createImageField($name, $type_name, $storage_settings = array(), $field_settings = array(), $widget_settings = array(), $formatter_settings = array(), $description = '') {
+    FieldStorageConfig::create(array(
+      'field_name' => $name,
+      'entity_type' => 'node',
+      'type' => 'image',
+      'settings' => $storage_settings,
+      'cardinality' => !empty($storage_settings['cardinality']) ? $storage_settings['cardinality'] : 1,
+    ))->save();
+
+    $field_config = FieldConfig::create([
+      'field_name' => $name,
+      'label' => $name,
+      'entity_type' => 'node',
+      'bundle' => $type_name,
+      'required' => !empty($field_settings['required']),
+      'settings' => $field_settings,
+      'description' => $description,
+    ]);
+    $field_config->save();
+
+    entity_get_form_display('node', $type_name, 'default')
+      ->setComponent($name, array(
+        'type' => 'image_image',
+        'settings' => $widget_settings,
+      ))
+      ->save();
+
+    entity_get_display('node', $type_name, 'default')
+      ->setComponent($name, array(
+        'type' => 'image',
+        'settings' => $formatter_settings,
+      ))
+      ->save();
+
+    return $field_config;
+
+  }
+
+  /**
    * Preview an image in a node.
    *
    * @param \Drupal\Core\Image\ImageInterface $image
reverted:
--- b/core/modules/image/tests/src/Kernel/ImageFieldCreationTrait.php
+++ /dev/null
@@ -1,70 +0,0 @@
-<?php
-
-namespace Drupal\Tests\image\Kernel;
-
-use Drupal\field\Entity\FieldConfig;
-use Drupal\field\Entity\FieldStorageConfig;
-
-/**
- * Provides a helper method for creating Image fields.
- */
-trait ImageFieldCreationTrait {
-
-  /**
-   * Create a new image field.
-   *
-   * @param string $name
-   *   The name of the new field (all lowercase), exclude the "field_" prefix.
-   * @param string $type_name
-   *   The node type that this field will be added to.
-   * @param array $storage_settings
-   *   (optional) A list of field storage settings that will be added to the
-   *   defaults.
-   * @param array $field_settings
-   *   (optional) A list of instance settings that will be added to the instance
-   *   defaults.
-   * @param array $widget_settings
-   *   (optional) Widget settings to be added to the widget defaults.
-   * @param array $formatter_settings
-   *   (optional) Formatter settings to be added to the formatter defaults.
-   * @param string $description
-   *   (optional) A description for the field. Defaults to ''.
-   */
-  protected function createImageField($name, $type_name, $storage_settings = array(), $field_settings = array(), $widget_settings = array(), $formatter_settings = array(), $description = '') {
-    FieldStorageConfig::create(array(
-      'field_name' => $name,
-      'entity_type' => 'node',
-      'type' => 'image',
-      'settings' => $storage_settings,
-      'cardinality' => !empty($storage_settings['cardinality']) ? $storage_settings['cardinality'] : 1,
-    ))->save();
-
-    $field_config = FieldConfig::create([
-      'field_name' => $name,
-      'label' => $name,
-      'entity_type' => 'node',
-      'bundle' => $type_name,
-      'required' => !empty($field_settings['required']),
-      'settings' => $field_settings,
-      'description' => $description,
-    ]);
-    $field_config->save();
-
-    entity_get_form_display('node', $type_name, 'default')
-      ->setComponent($name, array(
-        'type' => 'image_image',
-        'settings' => $widget_settings,
-      ))
-      ->save();
-
-    entity_get_display('node', $type_name, 'default')
-      ->setComponent($name, array(
-        'type' => 'image',
-        'settings' => $formatter_settings,
-      ))
-      ->save();
-
-    return $field_config;
-  }
-
-}