@Test
public void matches() {

    SmallestRingAtom matcher = new SmallestRingAtom(5, mock(IChemObjectBuilder.class));
    IAtom atom = mock(IAtom.class);
    when(atom.getProperty(SMARTSAtomInvariants.KEY)).thenReturn(
            new SMARTSAtomInvariants(mock(IAtomContainer.class), 0, 0, Collections.<Integer> singleton(5), 0, 0, 0,
                    0));
    assertTrue(matcher.matches(atom));
}