/guava/android/guava/src/com/google/common/graph/Traverser.java
return new Traversal<N>( graph) { Set<N> visited = new HashSet<>( ) ;
Set<N> visited = new HashSet<> ( ) ; return new Traversal<N> ( graph ) {
private abstract static class Traversal<N> { final SuccessorsFunction<N> successorFunction; Traversal(SuccessorsFunction<N> successorFunction) { this.successorFunction = successorFunction; } static <N> Traversal<N> inGraph(SuccessorsFunction<N> graph) { <extra_id_0> @Override @CheckForNull N visitNext(Deque<Iterator<? extends N>> horizon) { Iterator<? extends N> top = horizon.getFirst(); while (top.hasNext()) { N element = top.next();