Add a HashX signer to an account.

        Add a HashX signer to an account via a :class:`SetOptions
        <stellar_base.operation.SetOptions` operation. This is a helper
        function for :meth:`append_set_options_op`.

        :param hashx: The address of the new hashX signer.
        :type hashx: str, bytes
        :param int signer_weight: The weight of the new signer.
        :param str source: The source account that is adding a signer to its
            list of signers.
        :return: This builder instance.

def append_hashx_signer(self, hashx, signer_weight, source=None):
        """Add a HashX signer to an account.

        Add a HashX signer to an account via a :class:`SetOptions
        <stellar_base.operation.SetOptions` operation. This is a helper
        function for :meth:`append_set_options_op`.

        :param hashx: The address of the new hashX signer.
        :type hashx: str, bytes
        :param int signer_weight: The weight of the new signer.
        :param str source: The source account that is adding a signer to its
            list of signers.
        :return: This builder instance.

        """
        return self.append_set_options_op(
            signer_address=hashx,
            signer_type='hashX',
            signer_weight=signer_weight,
            source=source)