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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 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)