Creates an XDR Transaction object that represents this
        :class:`Transaction`.

def to_xdr_object(self):
        """Creates an XDR Transaction object that represents this
        :class:`Transaction`.

        """
        source_account = account_xdr_object(self.source)
        memo = self.memo.to_xdr_object()
        operations = [o.to_xdr_object() for o in self.operations]
        ext = Xdr.nullclass()
        ext.v = 0
        return Xdr.types.Transaction(source_account, self.fee, self.sequence,
                                     self.time_bounds, memo, operations, ext)