src/vs/base/browser/ui/grid/gridview.ts/fromAbsoluteBoundarySashes
function fromAbsoluteBoundarySashes(sashes: IBoundarySashes, orientation: Orientation): IRelativeBoundarySashes {
	if (orientation === Orientation.HORIZONTAL) {
		return { start: sashes.left, end: sashes.right, orthogonalStart: sashes.top, orthogonalEnd: sashes.bottom };
	} else {
		return { start: sashes.top, end: sashes.bottom, orthogonalStart: sashes.left, orthogonalEnd: sashes.right };
	}
}