private TraversalDescription friendToSuggestionTraversalDescription() {
   return Traversal.description()
       .breadthFirst()
       .relationships(ConnectionType.KNOWS)
       .evaluator(Evaluators.excludeStartPosition())
       .evaluator(Evaluators.atDepth(2));
 }
  private void canPreFilterNodes(TraversalDescription description) {
    Traverser traverser =
        description
            .uniqueness(Uniqueness.NONE)
            .evaluator(Evaluators.atDepth(2))
            .traverse(referenceNode());

    expectPaths(traverser, "1,2,6", "1,3,5", "1,4,5", "1,5,3", "1,5,4", "1,5,6");
  }