class DefaultValueMapTraversal implements ValueMapTraversal {

    @Override
    public long count() {
        return flow.apply(supplier.get()).count().tryNext().orElse(0L);
    }

      DefaultValueMapTraversal(Supplier<GraphTraversal<?, ?>> supplier, Function<GraphTraversal<?, ?>,
            GraphTraversal<Vertex, Map<String, Object>>> flow);

}