addEventListener('message', (e) => {
  if (e.data.command == 'ping') {
    postMessage({
      command: 'pong',
    });
    return;
  }

  let graph = new Graph(e.data);
  let layout = new Layout(graph);
  postMessage({
    generation: e.data.generation,
    steps: layout.getDrawSteps(),
  });
});

<!--# include file="Graph.js" -->
<!--# include file="Layout.js" -->

<!--# include file="utils.js" -->