@Test
public void hydroxyurea() {

    IAtomContainer container = new AtomContainer(9, 8, 0, 0);
    container.addAtom(atom("H", 0));
    container.addAtom(atom("O", 0));
    container.addAtom(atom("N", 0));
    container.addAtom(atom("H", 0));
    container.addAtom(atom("C", 0));
    container.addAtom(atom("O", 0));
    container.addAtom(atom("N", 0));
    container.addAtom(atom("H", 0));
    container.addAtom(atom("H", 0));
    container.addBond(0, 1, IBond.Order.SINGLE);
    container.addBond(1, 2, IBond.Order.SINGLE);
    container.addBond(2, 3, IBond.Order.SINGLE);
    container.addBond(2, 4, IBond.Order.SINGLE);
    container.addBond(4, 5, IBond.Order.DOUBLE);
    container.addBond(4, 6, IBond.Order.SINGLE);
    container.addBond(6, 7, IBond.Order.SINGLE);
    container.addBond(6, 8, IBond.Order.SINGLE);
    String[] expected = {"HO", "-O-", "NC=O", "HNCO", "CONN", "O=CN", "NC=O", "HNCO", "HNCO"};
    String[] actual = INSTANCE.symbolicTypes(container);
    Assert.assertArrayEquals(expected, actual);
}