Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/modules/image/src/ConfigurableImageEffectInterface.php

@@ -0,0 +1,23 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\image\ConfigurableImageEffectInterface.
+ */
+
+namespace Drupal\image;
+
+use Drupal\Core\Plugin\PluginFormInterface;
+
+/**
+ * Defines the interface for configurable image effects.
+ *
+ * @see \Drupal\image\Annotation\ImageEffect
+ * @see \Drupal\image\ConfigurableImageEffectBase
+ * @see \Drupal\image\ImageEffectInterface
+ * @see \Drupal\image\ImageEffectBase
+ * @see \Drupal\image\ImageEffectManager
+ * @see plugin_api
+ */
+interface ConfigurableImageEffectInterface extends ImageEffectInterface, PluginFormInterface {
+}