How to use the scratch-blocks.getMainWorkspace function in scratch-blocks

export default function (blockId) {
    // Not sure any better way to access the scratch-blocks workspace than this...
    const block = ScratchBlocks.getMainWorkspace().getBlockById(blockId);
    const blockSvg = block.getSvgRoot().cloneNode(true /* deep */);

    // Once we have the cloned SVG, do the rest in a setTimeout to prevent
    // blocking the drag end from finishing promptly.
    return new Promise(resolve => {
        setTimeout(() => {
            // Strip   entities that cannot be inlined
            blockSvg.innerHTML = blockSvg.innerHTML.replace(/ /g, ' ');

            // Create an <svg> element to put the cloned blockSvg inside
            const NS = 'http://www.w3.org/2000/svg';
            const svg = document.createElementNS(NS, 'svg');
            svg.appendChild(blockSvg);

            // Needs to be on the DOM to get CSS properties and correct sizing
            document.body.appendChild(svg);</svg>