--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wp/wp-includes/customize/class-wp-customize-filter-setting.php	Mon Oct 14 17:39:30 2019 +0200
@@ -0,0 +1,29 @@
+<?php
+/**
+ * Customize API: WP_Customize_Filter_Setting class
+ *
+ * @package WordPress
+ * @subpackage Customize
+ * @since 4.4.0
+ */
+
+/**
+ * A setting that is used to filter a value, but will not save the results.
+ *
+ * Results should be properly handled using another setting or callback.
+ *
+ * @since 3.4.0
+ *
+ * @see WP_Customize_Setting
+ */
+class WP_Customize_Filter_Setting extends WP_Customize_Setting {
+
+	/**
+	 * Saves the value of the setting, using the related API.
+	 *
+	 * @since 3.4.0
+	 *
+	 * @param mixed $value The value to update.
+	 */
+	public function update( $value ) {}
+}