src/vs/workbench/contrib/notebook/browser/viewModel/cellEdit.ts/JoinCellEdit/constructor
class JoinCellEdit:	constructor(
		public resource: URI,
		private index: number,
		private direction: 'above' | 'below',
		private cell: BaseCellViewModel,
		private selections: Selection[],
		private inverseRange: Range,
		private insertContent: string,
		private removedCell: BaseCellViewModel,
		private editingDelegate: IViewCellEditingDelegate,
	) {
		this._deletedRawCell = this.removedCell.model;
	}