src/vs/workbench/api/common/extHostNotebookDocument.ts/ExtHostNotebookDocument/_moveCell
class ExtHostNotebookDocument:	private _moveCell(index: number, newIdx: number, bucket: vscode.NotebookDocumentContentChange[]): void {
		const cells = this._cells.splice(index, 1);
		this._cells.splice(newIdx, 0, ...cells);
		const changes = [
			new RawContentChangeEvent(index, 1, cells.map(c => c.apiCell), []),
			new RawContentChangeEvent(newIdx, 0, [], cells)
		];
		for (const change of changes) {
			bucket.push(change.asApiEvent());
		}
	}