public virtual async Task <IDbContextTransaction> BeginTransactionAsync(
            IsolationLevel isolationLevel, CancellationToken cancellationToken = new CancellationToken())
        {
            await OpenAsync(cancellationToken);

            CurrentTransaction = new TestRelationalTransaction(this, await _realConnection.BeginTransactionAsync(isolationLevel, cancellationToken));
            return(CurrentTransaction);
        }