pub fn panic_blink_forever<L: Led>(leds: &mut [&L]) -> !
Blinks a recognizable pattern forever.
If a multi-color LED is used for the panic pattern, it is advised to turn off other LEDs before calling this method.
Generally, boards should blink red during panic if possible, otherwise choose the ‘first’ or most prominent LED. Some boards may find it appropriate to blink multiple LEDs (e.g. one on the top and one on the bottom), thus this method accepts an array, however most will only need one.