// throws jjtraveler.VisitFailure
public virtual void testBacktrack()
{
Increment i = new Increment();
Object initialState = i.getState();
(new Backtrack(i)).visit(n0);
Assertion.AssertNotNull(i.localState);
Assertion.AssertTrue(! initialState.Equals(i.localState));
Assertion.AssertEquals(initialState,i.getState());
}