code: def load_environment_config():
      
      mapper = {
          'interface': 'CAN_INTERFACE',
          'channel': 'CAN_CHANNEL',
          'bitrate': 'CAN_BITRATE',
      }
      return dict(
          (key, os.environ.get(val))
          for key, val in mapper.items()
          if val in os.environ
      )
docs: Loads config dict from environmental variables (if set):
  
      * CAN_INTERFACE
      * CAN_CHANNEL
      * CAN_BITRATE