code: def enter(self):
          
          self._communication.last_requested_line_number = self._line_number
          self._communication.send(LineConfirmation, self._line_number)
docs: Send a LineConfirmation to the controller.
  
          When this state is entered, a
          :class:`AYABInterface.communication.host_messages.LineConfirmation`
          is sent to the controller.
          Also, the :attr:`last line requested
          <AYABInterface.communication.Communication.last_requested_line_number>`
          is set.