src/vs/base/browser/ui/button/button.ts/ButtonWithDescription/constructor
class ButtonWithDescription:	constructor(container: HTMLElement, options: IButtonOptions) {
		super(container, options);

		this._element.classList.add('monaco-description-button');

		this._labelElement = document.createElement('div');
		this._labelElement.classList.add('monaco-button-label');
		this._element.appendChild(this._labelElement);

		this._descriptionElement = document.createElement('div');
		this._descriptionElement.classList.add('monaco-button-description');
		this._element.appendChild(this._descriptionElement);
	}