Getting the total volume of data transferred in a session

Have searched around for a way to get total amount of data (bytes) transferred through a session but so far no luck.
Anyone have the magical answer?
(using Powershell)

Regards

There's no magical answer.

martin wrote:

There's no magical answer.

I ended up solving this by looping through all files in the collection of successfully transferred files in the transfer result.

..
..
$script:amountOfData += (Get-Item $e.FileName).length
..
..

Thanks for sharing your solution.