A polygon with a label.

Supported `attrs` properties

Selector | Node | Description
--- | --- | ---
root | SVGGElement | Container of all nodes
body | SVGPolygonElement | Polygonal body of the shape
label | SVGTextElement | Text inside the body

    var polygon = new joint.shapes.standard.Polygon();
    polygon.resize(100, 100);
    polygon.position(250, 210);
    polygon.attr('root/title', 'joint.shapes.standard.Polygon');
    polygon.attr('label/text', 'Polygon');
    polygon.attr('body/refPoints', '0,10 10,0 20,10 10,20');
    polygon.addTo(graph);