src/vs/base/browser/ui/grid/gridview.ts/BranchNode/moveChild
class BranchNode:	moveChild(from: number, to: number): void {
		if (from === to) {
			return;
		}

		if (from < 0 || from >= this.children.length) {
			throw new Error('Invalid from index');
		}

		to = clamp(to, 0, this.children.length);

		if (from < to) {
			to--;
		}

		this.splitview.moveView(from, to);

		const child = this._removeChild(from);
		this._addChild(child, to);

		this.onDidChildrenChange();
	}