    linkView.sendToken(token, [duration], [callback])

Send a token along the link. `token` is an SVG element that will be animated along the link path for `duration` milliseconds (default is 1000ms). `callback` will be called once the token reaches the end of the link path. Example:

    // Send an SVG circle token along the link.
    paper.findViewByModel(link).sendToken(V('circle', { r: 7, fill: 'green' }).node)

Note that in the code above, we use the Vectorizer mini-library to create the SVG circle element.

Please see the Petri Net simulator demo for a full working example.