@classmethod
def from_port(cls, port_in, serial, *args, **kwargs):
    """Creates a layer from an existing serial object

        :param serial: Serial port object, either created using pyserial or from :func:`~pyrealtime.serial_layer.find_serial_port`.
        """
    layer = cls(*args, port_in=port_in, baud_rate=None, device_name=None,
        **kwargs)
    layer.ser = serial
    return layer
