src/vs/base/browser/ui/grid/gridview.ts/GridView/orientation
class GridView:	set orientation(orientation: Orientation) {
		if (this._root.orientation === orientation) {
			return;
		}

		const { size, orthogonalSize } = this._root;
		this.root = flipNode(this._root, orthogonalSize, size);
		this.root.layout(size, 0, { orthogonalSize, absoluteOffset: 0, absoluteOrthogonalOffset: 0, absoluteSize: size, absoluteOrthogonalSize: orthogonalSize });
		this.boundarySashes = this.boundarySashes;
	}