@Override public Map<Node<Double>, Double> getValidNeighbors(final Collection<? extends Node<Double>> neighborhood) { final Set<CellNode> linkedNodes = getNode().getNeighborsLinkWithJunction(j); return neighborhood.stream().filter(n -> linkedNodes.contains(n)) .collect(Collectors.<Node<Double>, Node<Double>, Double>toMap( n -> n, n -> 1.0)); }