code: def double_strike(self, action):
          '''Enable/cancel doublestrike printing
          
          Args:
              action: Enable or disable doublestrike printing. Options are 'on' and 'off'
          Returns:
              None
          Raises:
              RuntimeError: Invalid action.
          '''
          if action == 'on':
              action = 'G'
          elif action == 'off':
              action = 'H'
          else:
              raise RuntimeError('Invalid action for function doubleStrike. Options are on and off')
          self.send(chr(27)+actionf double_strike(self, action):
          '''Enable/cancel doublestrike printing
          
          Args:
              action: Enable or disable doublestrike printing. Options are 'on' and 'off'
          Returns:
              None
          Raises:
              RuntimeError: Invalid action.
          '''
          if action == 'on':
              action = 'G'
          elif action == 'off':
              action = 'H'
          else:
              raise RuntimeError('Invalid action for function doubleStrike. Options are on and off')
          self.send(chr(27)+action)
docs: Enable/cancel doublestrike printing
          
          Args:
              action: Enable or disable doublestrike printing. Options are 'on' and 'off'
          Returns:
              None
          Raises:
              RuntimeError: Invalid action.