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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_transaction(self, transaction_id):
 """Returns a Transaction object from the block store by its id. Params: transaction_id (str):
 The header_signature of the desired txn Returns: Transaction: The specified transaction Raises: ValueError: The transaction is not in the block store """

        payload = self._get_data_by_id(
            transaction_id, 'commit_store_get_transaction')

        txn = Transaction()
        txn.ParseFromString(payload)

        return txn