Description of problem: An utterly cool script I am porting to DNF asks users whether they want to download X Bytes on their disk. The X is a sum of download sizes of all needed rpm packages. Unfortunately, DNF does not expose "download size" in its API. I only found an undocumented member called "size" of the class Package. Version-Release number of selected component (if applicable): dnf-0.6.3-2.fc21.noarch
Correction: DNF "size" is Yum "downloadsize"
Documented here: https://github.com/rpm-software-management/dnf/commit/558593c7c7c9ff56def5d7ed93adffbf5a857dec