@Test
public void methane() {

    IAtomContainer container = new AtomContainer();
    container.addAtom(atom("C", 0));
    container.addAtom(atom("H", 0));
    container.addAtom(atom("H", 0));
    container.addAtom(atom("H", 0));
    container.addAtom(atom("H", 0));
    container.addBond(0, 1, SINGLE);
    container.addBond(0, 2, SINGLE);
    container.addBond(0, 3, SINGLE);
    container.addBond(0, 4, SINGLE);
    String[] expected = {"CR", "HC", "HC", "HC", "HC"};
    String[] actual = INSTANCE.symbolicTypes(container);
    Assert.assertArrayEquals(expected, actual);
}