@Override
    public void reset() {
        this.steps.forEach(Step::reset);
        this.finalEndStep.reset();
        this.lastTraverser = EmptyTraverser.instance();
        this.closed = false;
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/util/DefaultTraversal.java