Sets the LED trigger. A trigger is a kernel based source of LED events.
        Triggers can either be simple or complex. A simple trigger isn't
        configurable and is designed to slot into existing subsystems with
        minimal additional code. Examples are the `ide-disk` and `nand-disk`
        triggers.

        Complex triggers whilst available to all LEDs have LED specific
        parameters and work on a per LED basis. The `timer` trigger is an example.
        The `timer` trigger will periodically change the LED brightness between
        0 and the current brightness setting. The `on` and `off` time can
        be specified via `delay_{on,off}` attributes in milliseconds.
        You can change the brightness value of a LED independently of the timer
        trigger. However, if you set the brightness value to 0 it will
        also disable the `timer` trigger.

def trigger(self):
        """
        Sets the LED trigger. A trigger is a kernel based source of LED events.
        Triggers can either be simple or complex. A simple trigger isn't
        configurable and is designed to slot into existing subsystems with
        minimal additional code. Examples are the `ide-disk` and `nand-disk`
        triggers.

        Complex triggers whilst available to all LEDs have LED specific
        parameters and work on a per LED basis. The `timer` trigger is an example.
        The `timer` trigger will periodically change the LED brightness between
        0 and the current brightness setting. The `on` and `off` time can
        be specified via `delay_{on,off}` attributes in milliseconds.
        You can change the brightness value of a LED independently of the timer
        trigger. However, if you set the brightness value to 0 it will
        also disable the `timer` trigger.
        """
        self._trigger, value = self.get_attr_from_set(self._trigger, 'trigger')
        return value