class ImplicitToExplicit extends AbstractFunction<Graph,Graph> {

    static Edge toExplicitEdge(final Graph g, final Edge e) {
        final int u = e.either(), v = e.other(u);
        if (e.bond() == Bond.IMPLICIT) {
            return new Edge(u, v,
                            type(g.atom(u),
                                 g.atom(v)));
        }
        return e;
    }

}