@Override
    public void reset() {
        super.reset();
        if (null != this.emitTraversal)
            this.emitTraversal.reset();
        if (null != this.untilTraversal)
            this.untilTraversal.reset();
        if (null != this.repeatTraversal)
            this.repeatTraversal.reset();
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/branch/RepeatStep.java