docs: private Point restoreWindowLocation() {
  		Point result = null;
  		final String sizestr = preferences.get(prefnzPrefix+PREF_WINDOW_POSITION, null);
  		if (sizestr != null) {
  			int x = 0;
  			int y = 0;
  			final String[] sizes = sizestr.split("[,]");
  			try {
  				x = Integer.parseInt(sizes[0].trim());
  				y = Integer.parseInt(sizes[1].trim());
  			} catch (final Exception e) {
  				// ignoring, cause is prevented by default values;
  			}
  			if (x > 0 && y > 0) {
  				result = new Point(x, y);
  				if (logger.isDebugEnabled()) logger.debug("Restoring preference " + PREF_WINDOW_POSITION + "=" + result.x + "," + result.y);
  				this.setLocation(result);
  			}
  		}
  		return result;
  	}