public void setVertexFilter(final Traversal<Vertex, Vertex> vertexFilter) {
        if (!TraversalHelper.isLocalProperties(vertexFilter.asAdmin()))
            throw GraphComputer.Exceptions.vertexFilterAccessesIncidentEdges(vertexFilter);
        this.vertexFilter = vertexFilter.asAdmin().clone();
    }
Set the filter for selecting vertices from the source graph.
The vertex filter can only access the vertex, its properties, and its properties properties.
Vertex filters can not access the incident edges of the vertex.

@param vertexFilter The {@link Traversal} that will either let the vertex pass or not.
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/computer/GraphFilter.java