public boolean legalEdge(final Vertex vertex, final Edge edge) {
        return !this.graphFilter.hasEdgeFilter() || this.legalEdges.get(vertex.id()).contains(edge.id());
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
tinkergraph-gremlin/src/main/java/org/apache/tinkerpop/gremlin/tinkergraph/process/computer/TinkerGraphComputerView.java