ources/'
      let viewer = new DC.Viewer('viewer-container')
      let baseLayer = DC.ImageryLayerFactory.createImageryLayer(
        DC.ImageryType.AMAP,
        {
          style: 'img',
          crs: 'WGS84',
        }
      )
      viewer.addBaseLayer(baseLayer, {
        brightness: 0.1,
      })
      let layer = new DC.VectorLayer('layer')
      viewer.addLayer(layer)

      let polyline = new DC.Polyline('-75, 35; -80, 35').setStyle({
        width: 5,
        material: new DC.PolylineFlowMaterial