@Override
    public PeerPressureVertexProgramStep clone() {
        final PeerPressureVertexProgramStep clone = (PeerPressureVertexProgramStep) super.clone();
        clone.edgeTraversal = this.edgeTraversal.clone();
        return clone;
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/computer/traversal/step/map/PeerPressureVertexProgramStep.java