Add parameter and return descriptions for `WP_Customize_Widgets->get_setting_type()`.

See [31370]. See #31888.


git-svn-id: https://develop.svn.wordpress.org/trunk@32035 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-customize-widgets.php

@@ -105,10 +105,10 @@ final class WP_Customize_Widgets {
 	 * Get the widget setting type given a setting ID.
 	 *
 	 * @since 4.2.0
+	 * @access protected
 	 *
-	 * @param $setting_id
-	 *
-	 * @return string|null
+	 * @param $setting_id Setting ID.
+	 * @return string|null Setting type. Null otherwise.
 	 */
 	protected function get_setting_type( $setting_id ) {
 		static $cache = array();