studio-2017/wp-admin/network/theme-editor.php

<?php
/**
 * Theme editor network administration panel.
 *
 * @package WordPress
 * @subpackage Multisite
 * @since 3.1.0
 */

/** Load WordPress Administration Bootstrap */
require_once( dirname( __FILE__ ) . '/admin.php' );

require( ABSPATH . 'wp-admin/theme-editor.php' );