text: const test = require('tape');
  
  import Layer from '../../src/core/layer';
  import LayerTimeContext from '../../src/core/layer-time-context';
  import Marker from '../../src/shapes/marker';
  import MarkerBehavior from '../../src/behaviors/marker-behavior';
  import Timeline from '../../src/core/timeline';
  
  
  test('Marker', (assert) => {
    const trackDiv = document.createElement("div");
    document.body.appendChild(trackDiv);
    const timeline = new Timeline();
    const track = timeline.createTrack(trackDiv);
    let timeContext = new LayerTimeContext(timeline.timeContext)
    let data = [{ x: 3 }, { x: 6 }];
    let layer = new Layer('collection', data);
    layer.setTimeContext(timeContext);
    layer.configureShape(Marker);
    layer.setBehavior(new MarkerBehavior());
    layer.timeContext.duration = 12;
    timeline.addLayer(layer, track);
    timeline.tracks.render();
    timeline.tracks.update();
    const item0 = layer.items[0].getBoundingClientRect()
    const item1 = layer.items[1].getBoundingClientRect()
    const bodyClientRect = document.body.getBoundingClientRect();
  
    assert.equal(item0.left+item0.width/2 - bodyClientRect.left, 299.5);
    assert.equal(item1.left+item0.width/2 - bodyClientRect.left, 599.5);
    assert.end();
  });
  