sla-training_session2: createLayer single LayerSourceObject

<!DOCTYPE html>
<html>
  <head>
    <title>Actions on Feature Click | CartoDB.js</title>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
    <meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
    <link rel="shortcut icon" href="https://cartodb.com/assets/favicon.ico" />
    <link rel="stylesheet" href="https://cartodb-libs.global.ssl.fastly.net/cartodb.js/v3/3.15/themes/css/cartodb.css" />
    <script src="https://cartodb-libs.global.ssl.fastly.net/cartodb.js/v3/3.15/cartodb.js"></script>

<style>

html, body {
        height: 100%;
        padding: 0;
        margin: 0;
        position:relative;
      }
      #map {
        height: 100%;
        padding: 0;
        margin: 0;

}

</style>

</head>
    <body>
    <div id="map"></div>
    <script>
    function main() {
      var sublayer
      var map = L.map('map', { 
        zoomControl: true,
        center: [40.418709, -3.703277],
        zoom: 3
      });
      // add a nice baselayer from Stamen 
      L.tileLayer('https://{s}.tile.stamen.com/toner/{z}/{x}/{y}.png', {
        attribution: 'Stamen and CartoDB attribution'
      }).addTo(map);
       cartodb.createLayer(map, {
        user_name: 'trainer02',
        maps_api_template: "https://sla-training.cartodb.solutions:443/user/{user}",
        sql_api_template: "https://sla-training.cartodb.solutions:443/user/{user}",
        tiler_protocol: "http",
        tiler_domain: "sla-training.cartodb.solutions",
        tiler_port: "80",
        filter: "mapnik",
        type: 'cartodb',
        sublayers: [{
           sql: 'SELECT * FROM ne_10m_populated_places_simple',
           cartocss:'#ne_10m_populated_places_simple{  marker-fill-opacity: 0.9;  marker-line-color: #FFF;  marker-line-width: 0;  marker-line-opacity: 1;  marker-placement: point;  marker-multi-policy: largest;  marker-type: ellipse;  marker-fill: #FFCC00;  marker-allow-overlap: true; marker-clip: false; marker-comp-op: multiply;}',
        }]
      },{/*options here*/})
       .addTo(map)
       .on('done', function(layer) {
          //async actions here
       })
       .on('error', function(e){
       	console.log('error: '+e)
       });
    }

window.onload = main;

</script>
  </body>
</html>

https://cartodb-libs.global.ssl.fastly.net/cartodb.js/v3/3.15/cartodb.js