问如何从Cesium3DTileset控制原语的可见性

EN

//this is my checkbox elements
    <input type="checkbox" id="showCheckbox1" > geojson1<br>
    <input type="checkbox" id="showCheckbox2" > geojson2<br>
    <input type="checkbox" id="showCheckbox_1" > ion_1<br>
    <input type="checkbox" id="showCheckbox_2" > ion_2<br>


//this is my first try to control the visibility of geojson, and it goes well
    var obj1 = new Cesium.GeoJsonDataSource();
    obj.load('../DataSource/GeoJson/airport_cesium2.geojson')
    var obj2 = new Cesium.GeoJsonDataSource();
    obj2.load('../DataSource/GeoJson/LiangMau.geojson')

    function handleCheckbox(id,datasource){
        var checkbox = document.getElementById(id);
        checkbox.addEventListener('change', function() {
            // Checkbox state changed.
            if (checkbox.checked) {
                // Show if not shown.
                if (!viewer.dataSources.contains(datasource)) {
                    viewer.dataSources.add(datasource);
                }
            } else {
                // Hide if currently shown.
                if (viewer.dataSources.contains(datasource)) {
                    viewer.dataSources.remove(datasource);
                }
            }
        }, false);
    }
    handleCheckbox('showCheckbox1',obj1)
    handleCheckbox('showCheckbox2',obj2)


//then I try to control the visibility of 3DTile
    var obj_1 = new Cesium.Cesium3DTileset({
        url: Cesium.IonResource.fromAssetId(35386)
    })
    var obj_2 = new Cesium.Cesium3DTileset({
        url: Cesium.IonResource.fromAssetId(35381)
    })

    function handleCheckbox_(id,datasource){
        var checkbox = document.getElementById(id);
        checkbox.addEventListener('change', function() {
            // Checkbox state changed.
            if (checkbox.checked) {
                // Show if not shown.
                if (!scene.primitives.contains(datasource)) {
                    scene.primitives.add(datasource);
                }
            } else {
                // Hide if currently shown.
                if (scene.primitives.contains(datasource)) {
                    scene.primitives.remove(datasource);
                }
            }
        }, false);
    }
    handleCheckbox_('showCheckbox_1',obj_1)
    handleCheckbox_('showCheckbox_2',obj_2)