private void processLabelling(String labelMapping, List<Atom> atomList) throws StructureBuildingException {
		if (labelMapping.equals(NONE_LABELS_VAL) || labelMapping.length() == 0) {
			return;
		}
		if (labelMapping.equals(NUMERIC_LABELS_VAL)) {
			int atomNumber = 1;
			for (Atom atom : atomList) {
				atom.addLocant(Integer.toString(atomNumber++));
			}
		}
		else if(labelMapping.equals(FUSEDRING_LABELS_VAL)) {//fragment is a fusedring with atoms in the correct order for fused ring numbering
			//this will do stuff like changing labels from 1,2,3,4,5,6,7,8,9,10->1,2,3,4,4a,5,6,7,8,8a
			FragmentTools.relabelLocantsAsFusedRingSystem(atomList);
		}
		else{
			String[] labelMap = MATCH_SLASH.split(labelMapping, -1);//place slash delimited labels into an array
			int numOfAtoms = atomList.size();
			if (labelMap.length != numOfAtoms){
				throw new StructureBuildingException("Group numbering has been invalidly defined in resource file: labels: " +labelMap.length + ", atoms: " + numOfAtoms );
			}
			for (int i = 0; i < numOfAtoms; i++) {
				String labels[] = MATCH_COMMA.split(labelMap[i]);
				for (String label : labels) {
					if (label.length() > 0) {
						atomList.get(i).addLocant(label);
					}
				}
			}
		}
	}