@Override
        public boolean hasNext() {
            return !this.queue.isEmpty();
        }
Returns an unmodifiable {@code Iterable} over the nodes reachable from
{@code startNode}, in the order defined by the {@code algorithm}.

@param graph the graph
@param startNode the start node
@param <N> the node type
@return the traversal
common/src/main/java/me/lucko/luckperms/common/graph/TraversalAlgorithm.java