private bool SearchStackContains(Stack<TraversalInfo> stack, TraversalInfo ti)
        {
            if (!ti.IsFingerPrinted)
            {
                return false;
            }

            Fingerprint fp = ti.Fingerprint;

            var contains = stack.Where(t => (t.IsFingerPrinted && t.Fingerprint == fp)).Count() > 0;
            return contains;
        }