src/vs/workbench/contrib/markers/browser/markersTreeViewer.ts/MarkersViewModel/viewMode
class MarkersViewModel:	set viewMode(value: MarkersViewMode) {
		if (this._viewMode === value) {
			return;
		}

		this._viewMode = value;
		this._onDidChangeViewMode.fire(value);
		this.viewModeContextKey.set(value);
	}