snaptogrid on non-point elements

HTML

<link rel="stylesheet" href="http://jsxgraph.uni-bayreuth.de/distrib/jsxgraph.css">
<script src="http://jsxgraph.uni-bayreuth.de/~michael/jsxgraph-nightly/jsxgraphcore.js"></script>
<div id='box' class='jxgbox'></div>

CSS

#box {
    width:500px;
    height:500px;
}

JavaScript

var brd = JXG.JSXGraph.initBoard('box', {boundingbox: [-5,5,5,-5], keepaspectratio: true, grid: true});

var P = brd.create('point', [0, 0], {snapToPoints: true});
var Q = brd.create('point', [3, 2], {});
var l1 = brd.create('line', [P, Q], {snapToPoints: true});

var A = brd.create('point', [0, 0], {snapToPoints: true});
var B = brd.create('point', [-3, 2], {});
var l2 = brd.create('line', [A, B], {snapToPoints: false});