def METHOD_NAME() -> (float, bool, bool):
    if button_b.is_pressed:  # Debug key.
        return (3.0, False, True)
    if usb_power.value():
        return (5.0, True, False)
    # See the battery.py example for how this works.
    vdd = 1.24 * (65535 / vref_adc.read_u16())
    vbat = ((vbat_adc.read_u16() / 65535) * 3 * vdd)
    low_battery = False
    if vbat < LOW_BATTERY_VOLTAGE:
        low_battery = True
    return (vbat, False, low_battery)