Cesium.ClassificationPrimitive is not a constructor

I was trying to play around 3D tiles highlighting feature, I came across following example from Sandcastle.
var center = new Cesium.Cartesian3(1216378.730451297, -4736275.917774027, 4081266.871000864);
var modelMatrix = Cesium.Transforms.eastNorthUpToFixedFrame(center);
var hprRotation = Cesium.Matrix3.fromHeadingPitchRoll(new Cesium.HeadingPitchRoll(2.619728786416368, 0.0, 0.0));
var hpr = Cesium.Matrix4.fromRotationTranslation(hprRotation, new Cesium.Cartesian3(0.0, 0.0, -2.0));
Cesium.Matrix4.multiply(modelMatrix, hpr, modelMatrix);

var buildingHighlight = scene.primitives.add(new Cesium.ClassificationPrimitive({
    geometryInstances : new Cesium.GeometryInstance({
        geometry : Cesium.BoxGeometry.fromDimensions({
            vertexFormat : Cesium.PerInstanceColorAppearance.VERTEX_FORMAT,
            dimensions : new Cesium.Cartesian3(8.0, 5.0, 8.0)
        modelMatrix : modelMatrix,
        attributes : {
            color : Cesium.ColorGeometryInstanceAttribute.fromColor(new Cesium.Color(1.0, 0.0, 0.0, 0.5)),
            show : new Cesium.ShowGeometryInstanceAttribute(true)
        id : 'volume'
    classificationType : Cesium.ClassificationType.CESIUM_3D_TILE

I tried to use the same in my page, but I get first error for "Uncaught TypeError: Cannot read property 'CESIUM_3D_TILE' of undefined"

If I try to comment classificationType row, then I get "Uncaught TypeError: Cesium.ClassificationPrimitive is not a constructor" error. I see other Cesium features works fine, so Cesium is loaded properly.

What version of Cesium are you using? ClassificationType was added in Cesium 1.43 and ClassificationPrimitive was added in Cesium 1.36.

I'm using Cesium 1.44 version.