* @since	2.1.2
     */
    public Map<String, PdfLayer> getPdfLayers() {
    	if (documentOCG.isEmpty()) {
    		readOCProperties();
    	}
    	HashMap<String, PdfLayer> map = new HashMap<String, PdfLayer>();
    	PdfLayer layer;
    	String key;
    	for (PdfOCG pdfOCG : documentOCG) {
    		layer = (PdfLayer)pdfOCG;
    		if (layer.getTitle() == null) {
    			key = layer.getAsString(PdfName.NAME).toString();
    		}
    		else {
    			key = layer.getTitle();
    		}
    		if (map.containsKey(key)) {
    			int seq = 2;
    			String tmp = key + "(" + seq + ")";
    			while (map.containsKey(tmp)) {
    				seq++;
    				tmp = key + "(" + seq + ")";
    			}
    			key = tmp;
    		}
			map.put(key, layer);
    	}
    	return map;
    }