int length= fElements.length;
	private int fold() {		int length= fElements.length;				if (fAllowDuplicates) {			for (int i= 0; i != length; i++)							fFoldedIndices[i]= i; // identity mapping							return length;							} else {			int k= 0;			Label last= null;			for (int i= 0; i != length; i++) {				Label current= fLabels[i];				if (! current.equals(last)) {					fFoldedIndices[k]= i;					k++;					last= current;				}			}			return k;		}	}