[COLLECTIONS-674] Add drain method to CollectionUtils

[dota17]

For COLLECTIONS-674

[garydgregory]

You should check your tests before committing ;-) as the build fails.

WRT API name, removeRange is reminiscent of java.util.Arrays.copyOfRange(...) so it should be OK: we are removing a range of items specified by input args.

But we can do better than removeByDrain IMO. "ByDrain" is confusing since 'drain' and 'remove' are synonymous.

It feels to me like a removeCount is more precise.

You could reuse .CollectionUtils.checkIndexBounds(int)

You should also clean up your formatting as it seems all over the place, looking at it in GitHub at least.

[garydgregory]

Thank you!