Get ListboxItem from a the bound SelectedItem

In my case the ListBox is bound to an IEnumerable<Transaction>.  Where Transaction is a custom type in my domain model.

        <ListBox x:Name="TransactionListBox"
                     ItemsSource="{Binding Statement.Transactions}"
                     SelectedItem="{Binding SelectedTransaction}" />
... 

        private ListBoxItem GetSelectedListBoxItem()
        {
            object transaction = this.TransactionListBox.SelectedItem;
            return (ListBoxItem) this.TransactionListBox.ItemContainerGenerator.ContainerFromItem(transaction);
        }