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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 decode(self, tx):
 """ Decodes the given transaction. Args: tx: hex of transaction Returns: decoded transaction .. note:: Only supported for blockr.io at the moment. """

        if not isinstance(self._service, BitcoinBlockrService):
            raise NotImplementedError('Currently only supported for "blockr.io"')
        return self._service.decode(tx)