``` function performance( $visible = false ) { $stat = sprintf( '%d queries in %.3f seconds, using %.2fMB memory', get_num_queries(), timer_stop( 0, 3 ), memory_get_peak_usage() / 1024 / 1024 ); echo $visible ? $stat : "<!-- {$stat} -->" ; } add_action( 'wp_footer', 'performance', 20 ); ```