docs: def compressed_char(self, action):
          '''Enable/cancel compressed character printing
          
          Args:
              action: Enable or disable compressed character printing. Options are 'on' and 'off'
          Returns:
              None
          Raises:
              RuntimeError: Invalid action.
          '''
          if action == 'on':
              action = 15
          elif action == 'off':
              action = 18
          else:
              raise RuntimeError('Invalid action for function compressedChar. Options are on and off')
          self.send(chr(action))