src/vs/base/browser/ui/splitview/paneview.ts/PaneView/constructor
class PaneView:	constructor(container: HTMLElement, options: IPaneViewOptions = {}) {
		super();

		this.dnd = options.dnd;
		this.orientation = options.orientation ?? Orientation.VERTICAL;
		this.element = append(container, $('.monaco-pane-view'));
		this.splitview = this._register(new SplitView(this.element, { orientation: this.orientation }));
		this.onDidSashChange = this.splitview.onDidSashChange;
		this.onDidScroll = this.splitview.onDidScroll;
	}