Ignore channel

def get_state(self, channel):
        """
        Ignore channel
        """
        val = None
        if channel not in self._unit:
            return val
        if self._unit[channel] == 'l/h':
            val = ((1000 * 3600) / (self._delay[channel] * self._pulses[channel]))
        elif self._unit[channel] == 'm3/h':
            val = ((1000 * 3600) / (self._delay[channel] * self._pulses[channel]))
        elif self._unit[channel] == 'W':
            val = ((1000 * 1000 * 3600) / (self._delay[channel] * self._pulses[channel]))
            if val < 55:
                val = 0
        return round(val, 2)