@Override
    public SampleGlobalStep<S> clone() {
        final SampleGlobalStep<S> clone = (SampleGlobalStep<S>) super.clone();
        clone.probabilityTraversal = this.probabilityTraversal.clone();
        clone.detectedMutipleBy = this.detectedMutipleBy;
        return clone;
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/filter/SampleGlobalStep.java