code: def get_sequence(self):
          
          if not self.address:
              raise StellarAddressInvalidError('No address provided.')
  
          address = self.horizon.account(self.address)
          return int(address.get('sequence'))
docs: Get the sequence number for a given account via Horizon.
  
          :return: The current sequence number for a given account
          :rtype: int