code: def deleteStoredSms(self, index, memory=None):
          
          self._setSmsMemory(readDelete=memory)
          self.write('AT+CMGD={0},0'.format(index))
docs: Deletes the SMS message stored at the specified index in modem/SIM card memory
          
          :param index: The index of the SMS message in the specified memory
          :type index: int
          :param memory: The memory type to delete from. If None, use the current default SMS read/delete memory
          :type memory: str or None
          
          :raise CommandError: if unable to delete the stored message