src/vs/workbench/contrib/preferences/browser/keybindingWidgets.ts/DefineKeybindingOverlayWidget/start
class DefineKeybindingOverlayWidget:	start(): Promise<string | null> {
		if (this._editor.hasModel()) {
			this._editor.revealPositionInCenterIfOutsideViewport(this._editor.getPosition(), ScrollType.Smooth);
		}
		const layoutInfo = this._editor.getLayoutInfo();
		this._widget.layout(new dom.Dimension(layoutInfo.width, layoutInfo.height));
		return this._widget.define();
	}