Simple createLayer https://bl.ocks.org/knownasilya/26336a57eefb63ecbe14266098ac2f10

<!doctype html>
<html>
<head>
<title>createLayer</title>
<link href='https://fonts.googleapis.com/css?family=Alike' rel='stylesheet' type='text/css'>
    <style>
      html, body, #map {
        height: 100%;
        padding: 0;
        margin: 0;
      }
    </style>
    <link rel="stylesheet" href="https://libs.cartocdn.com/cartodb.js/v3/3.15.9/themes/css/cartodb.css" />
    <script src="https://libs.cartocdn.com/cartodb.js/v3/3.15.9/cartodb.js"></script>
    <script type="text/javascript">
    function main() {
        var layer = L.tileLayer('https://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}.png', {
          attribution: '&copy; <a href="https://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors, &copy; <a href="https://cartodb.com/attributions">CartoDB</a>'
        });

var map = L.map('map', {
            center: [40.7127837, -74.0059413],
            zoom: 6
        });

map.addLayer(layer);
        
        var bounds = [[-42, -126],[58, 154]];
        map.fitBounds(bounds);
        
        cartodb.createLayer(map, 'https://appgeo.cartodb.com/u/clientdemos/api/v2/viz/ab40dbb2-2361-11e6-b6ec-0e31c9be1b51/viz.json')
        .addTo(map);
    }

window.onload = main;
</script>

</head>
<body>
    <div id="map"></div>
	<canvas id="test" style="background-color: black;"></canvas>
</body>
</html>

https://libs.cartocdn.com/cartodb.js/v3/3.15.9/cartodb.js