@Override
        public GraphComputer vertexProperties(Traversal<Vertex, ? extends Property<?>> vertexPropertyFilter) {
            throw GraphComputer.Exceptions.graphFilterNotSupported();
        }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/process/computer/GraphComputerTest.java