Create a new builder based off of this one with its sequence number
        incremented.

        :return: A new Builder instance
        :rtype: :class:`Builder`

def next_builder(self):
        """Create a new builder based off of this one with its sequence number
        incremented.

        :return: A new Builder instance
        :rtype: :class:`Builder`

        """
        sequence = self.sequence + 1
        next_builder = Builder(
            horizon_uri=self.horizon.horizon_uri,
            address=self.address,
            network=self.network,
            sequence=sequence,
            fee=self.fee)
        next_builder.keypair = self.keypair
        return next_builder