public override void CleanUp()
{
//The pair handler cleanup will get rid of contacts.
foreach (var pairHandler in subPairs.Values)
{
pairHandler.CleanUp();
//Don't forget to give the pair back to the factory!
//There'd be a lot of leaks otherwise.
pairHandler.Factory.GiveBack(pairHandler);
}
subPairs.Clear();
//don't need to remove constraints directly from our group, since cleaning up our children should get rid of them.
base.CleanUp();
//Child type needs to null out the references.
}