@Test
public void writeParentAtomSgroupAsList() throws Exception{

    IAtomContainer mol  = builder.newAtomContainer();
    IAtom          atom = builder.newAtom();
    atom.setSymbol("C");
    mol.addAtom(atom);
    // build multiple group Sgroup
    Sgroup sgroup = new Sgroup();
    sgroup.setType(SgroupType.CtabMultipleGroup);
    sgroup.addAtom(atom);
    List<IAtom> patoms = new ArrayList<>();
        patoms.add(atom);
    sgroup.putValue(SgroupKey.CtabParentAtomList, patoms);
    mol.setProperty(CDKConstants.CTAB_SGROUPS,
            Collections.singletonList(sgroup));
    StringWriter sw = new StringWriter();
    try (MDLV2000Writer mdlw = new MDLV2000Writer(sw)) {
        mdlw.write(mol);
    }
    assertThat(sw.toString(), containsString("SPA   1  1"));
}