code: private static void validateNewAddition(Vector paths, ExpressionOwner owner, 
                                            LocPathIterator path) 
  		throws RuntimeException 
    {
    	assertion(owner.getExpression() == path, "owner.getExpression() != path!!!");
  	int n = paths.size();
  	// There should never be any duplicates in the list!
  	for(int i = 0; i < n; i++)
  	{
  		ExpressionOwner ew = (ExpressionOwner)paths.elementAt(i);
  		assertion(ew != owner, "duplicate owner on the list!!!");
  		assertion(ew.getExpression() != path, "duplicate expression on the list!!!");
  	}
    }
docs: Validate some assumptions about the new LocPathIterator and it's
  owner and the state of the list.