WordPress sandbox environment setup template

/**
 * WordPress sandbox environment setup template.
 *
 * @see https://wpcodebook.com/wordpress-sandbox-environment-setup-template/
 * @see https://example.com/wp-admin/?sandbox
 */
add_action( 'admin_init', function () {
	if ( ! isset( $_GET['sandbox'] ) ) {
		return;
	}
	// TODO
	die();
} );