A couple of years ago commit a4f50e3b introduced a new checkstyle
validation in oVirt Engine that enforces the order of the imports since
some of the developers did not use the standards from the Engine code
format and this caused a situation where some commits included aside for
the actual code also a reformat of the imports that was unrelated to the
patch.
After the validation was added the situation got better but there were
still no 100% alignment since the Engine code format also defines that
there should be that there should be a blank line between the different
import groups and this was not enforced, a fact that caused some patches to
add lines and some remove lines between the imports.
Today I've merged commit bf298fed that fixes all the imports as per the
project standard and commit 1c6b710 that adds a checkstyle validation that
enforces this change so note that from now on you should maintain that.
You can add the code format which is located in Engine root under
config/engine-code-format.xml to your IDE to have the imports arranged
automatically.