createFlyout = function (workspace) {
    let xmlList = [];
    const button = document.createElement('button');
    button.setAttribute('text', 'Create Typed Variable');
    button.setAttribute('callbackKey', 'CREATE_TYPED_VARIABLE');

    xmlList.push(button);

    const blockList = Blockly.VariablesDynamic.flyoutCategoryBlocks(workspace);
    xmlList = xmlList.concat(blockList);
    return xmlList;
  }
Create the typed variable flyout.
@param {!Blockly.WorkspaceSvg} workspace The Blockly workspace.
@returns {!Array.<!Element>} Array of XML block elements.