@Override
    public List<Traversal.Admin<Vertex, Edge>> getLocalChildren() {
        return Collections.singletonList(this.edgeTraversal.get());
    }
@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