lib/container: Clean up FlagsContainer.
lib/container: Clean up FlagsContainer.

riggs/construct,riggs/construct,gkonstantyno/construct,MostAwesomeDude/construct,mosquito/construct,MostAwesomeDude/construct,mosquito/construct,0000-bigtree/construct,0000-bigtree/construct,gkonstantyno/construct