@Override
    public Set<TraverserRequirement> getRequirements() {
        return Collections.singleton(TraverserRequirement.BULK);
    }
@author Bob Briody (http://bobbriody.com)
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/filter/RangeGlobalStep.java