Backup Exec 2012 and Vmware lazy zeroes disks

Hello

I’d like to be sure how backup exec and its VM agent does backup of Vmware lazy zeroes disk. Does it  backup of unused blocks or not ?

I realize that empty block are skipped but what about unused not zeroes blocks ??

In NBU Vmware policy there is checkbox which allows to skip unused block, but the question is about BE.

Regards

JS