src/vs/workbench/browser/parts/editor/editorPart.ts/EditorPart/toGridViewOrientation
class EditorPart:	private toGridViewOrientation(orientation: GroupOrientation, fallback: Orientation): Orientation {
		if (typeof orientation === 'number') {
			return orientation === GroupOrientation.HORIZONTAL ? Orientation.HORIZONTAL : Orientation.VERTICAL;
		}

		return fallback;
	}