This isn't being used at all within IRHydra, but [Rank.sort()](http://help.eclipse.org/kepler/topic/org.eclipse.draw2d.doc.isv/reference/api/org/eclipse/draw2d/graph/Rank.html#sort()) does still exist on the latest eclipse.draw2d release. I'm not sure whether it's better to stay closer to their original interface or just remove something that will almost certainly not be used from this dart port. Being that it's deprecated and unused, I guess my vote is just to remove it.