class Fragment implements Iterable<Atom> {

	int getChainLength() {
		int length = 0;
		Atom next = getAtomByLocant(Integer.toString(length + 1));
		Atom previous = null;
		while (next != null){
			if (previous != null && previous.getBondToAtom(next) == null){
				break;
			}
			length++;
			previous = next;
			next = getAtomByLocant(Integer.toString(length + 1));
		}
		return length;
	}

	  Fragment(Element tokenEl);
	  Fragment(String type);

}