* @param specInfo
	 * @return BitSet or null in certain cases
	 */
	BitSet getAtomBits(String setType, String specInfo) {
		if (setType.equals("IdentifierOrNull"))
			return getIdentifierOrNull(specInfo);
		if (setType.equals("SpecAtom"))
			return getSpecAtom(specInfo);
		if (setType.equals("SpecName"))
			return getSpecName(specInfo);
		if (setType.equals("SpecAlternate"))
			return getSpecAlternate(specInfo);
		if (setType.equals("SpecModel"))
			return getSpecModel(specInfo);
		return null;
	}