public boolean isComplete() {
        for (Transaction<V, R> transaction : transactions) {
            if (!transaction.isComplete()) {
                return false;
            }
        }
        return true;
    }
public boolean isComplete ( ) { for ( Transaction < V , R > transaction : transactions ) { if ( ! transaction . isComplete ( ) ) { return false ; } } return true ; }
Returns the completion status of the set of transactions.  Will only return complete = true if all the transactions
have completed successfully.

@return transaction completion status