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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 _get_block_transactions( self, transaction_root: Hash32, transaction_class: Type['BaseTransaction']) -> Iterable['BaseTransaction']: """ Memoizable version of `get_block_transactions` """

        for encoded_transaction in self._get_block_transaction_data(self.db, transaction_root):
            yield rlp.decode(encoded_transaction, sedes=transaction_class)