How to use the @here/harp-text-canvas.FontCatalog.load function in @here/harp-text-canvas

scene.add(cube);

        // Init TextCanvas
        textRenderStyle = new TextRenderStyle({
            fontSize: { unit: FontUnit.Pixel, size: 64.0, backgroundSize: 8.0 },
            color: new THREE.Color(0xff0000),
            backgroundColor: new THREE.Color(0x000000),
            backgroundOpacity: 1.0
        });
        textLayoutStyle = new TextLayoutStyle({
            horizontalAlignment: HorizontalAlignment.Center,
            verticalAlignment: VerticalAlignment.Below,
            lineWidth: 1024.0,
            wrappingMode: WrappingMode.Character
        });
        FontCatalog.load("resources/fonts/Default_FontCatalog.json", 2048)
            .then((loadedFontCatalog: FontCatalog) => {
                textCanvas = new TextCanvas({
                    renderer: webglRenderer,
                    fontCatalog: loadedFontCatalog,
                    maxGlyphCount: characterCount
                });
                loadedFontCatalog.loadCharset(textSample, textRenderStyle).then(() => {
                    assetsLoaded = true;
                });
            })
            .catch(error => {
                // tslint:disable-next-line:no-console
                console.error(error);
            });

        // Init Debug Visualization

document.body.appendChild(stats.dom);
        window.addEventListener("resize", onWindowResize);

        camera = new THREE.OrthographicCamera(
            -window.innerWidth / 2.0,
            window.innerWidth / 2.0,
            window.innerHeight / 2.0,
            -window.innerHeight / 2.0
        );
        camera.position.z = 1.0;
        camera.near = 0.0;
        camera.updateProjectionMatrix();

        // Init TextCanvas
        // snippet:textcanvas_minimal_0.ts
        FontCatalog.load("resources/fonts/Default_FontCatalog.json", 16).then(
            // end:textcanvas_minimal_0.ts
            (loadedFontCatalog: FontCatalog) => {
                // snippet:textcanvas_minimal_1.ts
                textCanvas = new TextCanvas({
                    renderer: webglRenderer,
                    fontCatalog: loadedFontCatalog,
                    maxGlyphCount: 12
                });
                // end:textcanvas_minimal_1.ts
                // snippet:textcanvas_minimal_2.ts
                loadedFontCatalog.loadCharset("Hello World!", new TextRenderStyle()).then(() => {
                    assetsLoaded = true;
                    // end:textcanvas_minimal_2.ts
                    // snippet:textcanvas_minimal_3.ts
                    textCanvas.addText("Hello World!", new THREE.Vector3(0, 0, 0));
                    // end:textcanvas_minimal_3.ts

document.body.appendChild(webglRenderer.domElement);
        document.body.appendChild(stats.dom);
        window.addEventListener("resize", onWindowResize);

        camera = new THREE.OrthographicCamera(
            -window.innerWidth / 2.0,
            window.innerWidth / 2.0,
            window.innerHeight / 2.0,
            -window.innerHeight / 2.0
        );
        camera.position.z = 1.0;
        camera.near = 0.0;
        camera.updateProjectionMatrix();

        // Init TextCanvas
        FontCatalog.load("resources/fonts/Default_FontCatalog.json", 16).then(
            (loadedFontCatalog: FontCatalog) => {
                textCanvas = new TextCanvas({
                    renderer: webglRenderer,
                    fontCatalog: loadedFontCatalog,
                    maxGlyphCount: 24
                });
                loadedFontCatalog
                    .loadCharset(textSampleA + textSampleB, new TextRenderStyle())
                    .then(() => {
                        assetsLoaded = true;
                    });
            }
        );

        // Init bounds Visualization
        initDebugBounds();

camera.updateProjectionMatrix();

        // Init textLayoutManager
        textLayoutStyle = new TextLayoutStyle({
            horizontalAlignment: HorizontalAlignment.Center,
            verticalAlignment: VerticalAlignment.Below,
            lineWidth: window.innerWidth
        });
        textRenderStyle = new TextRenderStyle({
            fontSize: {
                unit: FontUnit.Pixel,
                size: 8.0,
                backgroundSize: 0.0
            }
        });
        FontCatalog.load("resources/fonts/Default_FontCatalog.json", 2048).then(
            (loadedFontCatalog: FontCatalog) => {
                textCanvas = new TextCanvas({
                    renderer: webglRenderer,
                    fontCatalog: loadedFontCatalog,
                    maxGlyphCount: characterCount
                });
                loadedFontCatalog.loadCharset(textSample, textRenderStyle).then(() => {
                    assetsLoaded = true;
                    guiOptions.update();
                });
            }
        );

        // Init Debug Visualization
        initDebugBounds();
        initDebugGrid();

window.innerWidth / 2.0,
            window.innerHeight / 2.0,
            -window.innerHeight / 2.0
        );
        camera.position.z = 1.0;
        camera.near = 0.0;
        camera.updateProjectionMatrix();

        // Init TextCanvas
        textRenderStyle = new TextRenderStyle({
            fontSize: { unit: FontUnit.Pixel, size: 64.0, backgroundSize: 8.0 },
            color: new THREE.Color(0xff0000),
            backgroundColor: new THREE.Color(0x000000),
            backgroundOpacity: 1.0
        });
        FontCatalog.load("resources/fonts/Default_FontCatalog.json", 2048).then(
            (loadedFontCatalog: FontCatalog) => {
                textCanvas = new TextCanvas({
                    renderer: webglRenderer,
                    fontCatalog: loadedFontCatalog,
                    minGlyphCount: 16,
                    maxGlyphCount: characterCount
                });
                loadedFontCatalog.loadCharset(textSample, textRenderStyle).then(() => {
                    assetsLoaded = true;
                });
            }
        );

        // Init Debug Visualization
        initDebugBounds();
        initDebugGrid();

}
            gl_FragColor = color;
        }`;

        // Init TextCanvas
        textRenderStyle = new TextRenderStyle({
            fontSize: {
                unit: FontUnit.Percent,
                size: 300.0,
                backgroundSize: 0.0
            }
        });
        textLayoutStyle = new TextLayoutStyle({
            horizontalAlignment: HorizontalAlignment.Center
        });
        FontCatalog.load("resources/fonts/Default_FontCatalog.json", 16).then(
            (loadedFontCatalog: FontCatalog) => {
                // snippet:textcanvas_material_0.ts
                materialA = createSdfTextMaterial({
                    fontCatalog: loadedFontCatalog,
                    vertexSource: materialVertexSource,
                    fragmentSource: materialFragmentSourceA
                });
                materialA.uniforms.time = new THREE.Uniform(0.0);
                materialB = createSdfTextMaterial({
                    fontCatalog: loadedFontCatalog,
                    vertexSource: materialVertexSource,
                    fragmentSource: materialFragmentSourceB
                });
                materialB.uniforms.time = new THREE.Uniform(0.0);
                textCanvas = new TextCanvas({
                    renderer: webglRenderer,

document.body.appendChild(webglRenderer.domElement);
        document.body.appendChild(stats.dom);
        window.addEventListener("resize", onWindowResize);

        camera = new THREE.OrthographicCamera(
            -window.innerWidth / 2.0,
            window.innerWidth / 2.0,
            window.innerHeight / 2.0,
            -window.innerHeight / 2.0
        );
        camera.position.z = 1.0;
        camera.near = 0.0;
        camera.updateProjectionMatrix();

        // Init TextCanvas
        FontCatalog.load("resources/fonts/Default_FontCatalog.json", 16).then(
            (loadedFontCatalog: FontCatalog) => {
                textCanvas = new TextCanvas({
                    renderer: webglRenderer,
                    fontCatalog: loadedFontCatalog,
                    maxGlyphCount: 12
                });
                loadedFontCatalog.loadCharset("0123456789", new TextRenderStyle()).then(() => {
                    assetsLoaded = true;
                    addText();
                });
            }
        );

        // Animation loop
        animate();
    }

window.innerHeight / 2.0,
            -window.innerHeight / 2.0
        );
        camera.position.z = 1.0;
        camera.near = 0.0;
        camera.updateProjectionMatrix();

        // Init TextCanvas
        textRenderStyle = new TextRenderStyle({
            fontSize: {
                unit: FontUnit.Percent,
                size: 200.0,
                backgroundSize: 0.0
            }
        });
        FontCatalog.load("resources/fonts/Default_FontCatalog.json", 32).then(
            (loadedFontCatalog: FontCatalog) => {
                textCanvas = new TextCanvas({
                    renderer: webglRenderer,
                    fontCatalog: loadedFontCatalog,
                    maxGlyphCount: 64
                });
                loadedFontCatalog
                    .loadCharset("black" + "red" + "green" + "blue", textRenderStyle)
                    .then(() => {
                        assetsLoaded = true;
                    });
            }
        );

        // Animation loop
        animate();