These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.53 s (backtrack: 0/20).

[ebuild  NS    ] app-text/docbook-xml-dtd-4.3-r2:4.3::gentoo [4.1.2-r7:4.1.2::gentoo, 4.2-r3:4.2::gentoo, 4.4-r3:4.4::gentoo, 4.5-r2:4.5::gentoo] 82 KiB
[ebuild  N     ] sys-apps/bubblewrap-0.13.0::gentoo  USE="-debug (-selinux) -test" 127 KiB

Total: 2 packages (1 new, 1 in new slot), Size of downloads: 209 KiB