src/vs/base/browser/ui/keybindingLabel/keybindingLabel.ts/KeybindingLabel/constructor
class KeybindingLabel:	constructor(container: HTMLElement, private os: OperatingSystem, options?: KeybindingLabelOptions) {
		this.options = options || Object.create(null);

		this.labelBackground = this.options.keybindingLabelBackground;
		this.labelForeground = this.options.keybindingLabelForeground;
		this.labelBorder = this.options.keybindingLabelBorder;
		this.labelBottomBorder = this.options.keybindingLabelBottomBorder;
		this.labelShadow = this.options.keybindingLabelShadow;

		this.domNode = dom.append(container, $('.monaco-keybinding'));
		this.didEverRender = false;
		container.appendChild(this.domNode);
	}