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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 _validate_depedencies(batches):
 """Validates the transaction dependencies for the transactions contained within the sequence of batches. Given that all the batches are expected to to be executed for the genesis blocks, it is assumed that any dependent transaction will proceed the depending transaction. """

    transaction_ids = set()
    for batch in batches:
        for txn in batch.transactions:
            txn_header = TransactionHeader()
            txn_header.ParseFromString(txn.header)

            if txn_header.dependencies:
                unsatisfied_deps = [
                    id for id in txn_header.dependencies
                    if id not in transaction_ids
                ]
                if unsatisfied_deps:
                    raise CliException(
                        'Unsatisfied dependency in given transactions:'
                        ' {}'.format(unsatisfied_deps))

            transaction_ids.add(txn.header_signature)