Set `d` attribute of the `<path>` subelement relatively to the dimensions and position of the element referenced by the selector in the `ref` attribute. The `refD` path data is scaled so that the path's dimensions match the reference element's dimensions, and translated so that the path's origin matches the origin of the reference element.

The original path data offset is preserved. This means that if the top-left corner of the `refD` bounding box does not lie at `0,0`, the gap between the path and origin is preserved in the rendered shape, as well.

    var Path = joint.dia.Element.define('examples.Path', {
        attrs: {
            path: {
                refDKeepOffset: 'M 10 10 30 10 30 30 z', // path offset is 10,10
                fill: 'red',
                stroke: 'black'
            }
        }
    }, {
        markup: 'path'
    });

    var p = (new Path()).resize(40, 40).addTo(graph);
    // the rendered path's `d` attribute will be 'M 10 10 50 10 50 50 z'
    // can be obtained by `p.findView(paper).vel.findOne('path').attr('d');`