@Override
        public Iterator<Vertex> vertices(final Direction direction, final String... edgeLabels) {
            if (state.equals(State.MAP_REDUCE))
                throw GraphComputer.Exceptions.incidentAndAdjacentElementsCanNotBeAccessedInMapReduce();
            return IteratorUtils.map(this.getBaseVertex().vertices(direction, edgeLabels), v -> v.equals(starVertex) ? starVertex : new ComputerAdjacentVertex(v));
        }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/computer/util/ComputerGraph.java