code: def init_hardware(self, serial=None, device_number=ANY_MODULE):
          
          if not self._hw_is_initialized:
              # initialize hardware either by device number or serial
              if serial is None:
                  UcanInitHardwareEx(byref(self._handle), device_number, self._callback_ref, None)
              else:
                  UcanInitHardwareEx2(byref(self._handle), serial, self._callback_ref, None)
              self._hw_is_initialized = True
docs: Initializes the device with the corresponding serial or device number.
  
          :param int or None serial: Serial number of the USB-CANmodul.
          :param int device_number: Device number (0 – 254, or :const:`ANY_MODULE` for the first device).