text: <!DOCTYPE html>
  <html>
  <head>
      <title>Mapbox GL JS debug page</title>
      <meta charset='utf-8'>
      <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=no">
      <link rel='stylesheet' href='../dist/mapbox-gl.css' />
      <style>
          #map { width: 1200px; height: 800px;  }
      </style>
  </head>
  
  <body>
  <div id='map'></div>
  
  <script src='../dist/mapbox-gl-dev.js'></script>
  <script src='../debug/access_token_generated.js'></script>
  <script>
  
  var map = window.map = new mapboxgl.Map({
      container: 'map',
      style: 'mapbox://styles/mapbox/streets-v11',
      center: [0, 0],
      zoom: 4
  });
  
  var radius = 30;
  
  function line(angle, radius) {
      return {
          "type": "Feature",
          "geometry": {
              "type": "LineString",
              "coordinates": [
                  [-Math.cos(angle) * radius, -Math.sin(angle) * radius + 1],
                  [Math.cos(angle) * radius, Math.sin(angle) * radius + 1],
              ]
          }
      };
  }
  
  function crossWithAngle(angle) {
      return {
          "type": "FeatureCollection",
          "features": [
              line(angle - Math.PI / 4, radius),
              line(angle + Math.PI / 4, radius)
          ]
      };
  }
  
  map.on('load', function () {
      // Add a source and layer displaying a point which will be animated in a circle.
      map.addSource('lines', {
          "type": "geojson",
          "data": crossWithAngle(0)
      });
  
      map.addLayer({
          "id": "lines",
          "source": "lines",
          "type": "line",
          "paint": {
              "line-width": 4,
              "line-color": "#007cbf"
          }
      });
  
      map.addLayer({
          "id": "dot",
          "source": "lines",
          "type": "circle",
          "paint": {
              "circle-radius": 10,
              "circle-color": "#007cbf"
          }
      });
  
      var updates = 0;
  
      map.on('data', function (d) {
          if (d.sourceDataType === 'content') {
              updates++;
          }
      });
  
      setInterval(function () {
          console.log(updates + ' updates per second');
          updates = 0;
      }, 1000);
  
      function animateMarker(timestamp) {
          // Update the data to a new position based on the animation timestamp. The
          // divisor in the expression `timestamp / 1000` controls the animation speed.
          map.getSource('lines').setData(crossWithAngle(timestamp / 1000));
  
          // Request the next frame of the animation.
          requestAnimationFrame(animateMarker);
      }
  
      // Start the animation.
      animateMarker(0);
  });
  </script>
  
  </body>
  </html>
  