code: def shutdown(self, channel=Channel.CHANNEL_ALL, shutdown_hardware=True):
          
          # shutdown each channel if it's initialized
          for _channel, is_initialized in self._ch_is_initialized.items():
              if is_initialized and (_channel == channel or channel == Channel.CHANNEL_ALL or shutdown_hardware):
                  UcanDeinitCanEx(self._handle, _channel)
                  self._ch_is_initialized[_channel] = False
  
          # shutdown hardware
          if self._hw_is_initialized and shutdown_hardware:
              UcanDeinitHardware(self._handle)
              self._hw_is_initialized = False
              self._handle = Handle(INVALID_HANDLE)
docs: Shuts down all CAN interfaces and/or the hardware interface.
  
          :param int channel:
              CAN channel, to be used (:data:`Channel.CHANNEL_CH0`, :data:`Channel.CHANNEL_CH1` or
              :data:`Channel.CHANNEL_ALL`)
          :param bool shutdown_hardware: If true then the hardware interface will be closed too.