@Test public void simple_augment() throws Exception {

    Graph g = Graph.fromSmiles("cccc");
    Matching m = Matching.empty(g);
    m.match(1, 2);
    MaximumMatching.maximise(g, m, 2);
    assertThat(m.matches(),
               hasItems(Tuple.of(0, 1),
                        Tuple.of(2, 3)));
}