Add existing leaflet polygons to an existing leaflet layer
<p>I have a bunch of polygons which are stored in a database. I would like to add them to the map in such a way that they can be edited using the <a href="https://github.com/Leaflet/Leaflet.draw" rel="noreferrer">leaflet-draw</a> toolbar. Although, now the polygons get added to the map, I am unable edit them.</p>

<p>I think this is because they are not added to the <a href="http://leafletjs.com/reference.html#layergroup" rel="noreferrer"><code>layerGroup()</code></a> to which newly drawn shapes are added.</p>

<p>Please help.</p>