src/vs/workbench/contrib/notebook/browser/notebookEditorWidget.ts/NotebookEditorWidget/_validateCellFocusMode
class NotebookEditorWidget:	private _validateCellFocusMode(cell: ICellViewModel) {
		if (cell.focusMode !== CellFocusMode.Editor) {
			return;
		}

		if (this._lastCellWithEditorFocus && this._lastCellWithEditorFocus !== cell) {
			this._lastCellWithEditorFocus.focusMode = CellFocusMode.Container;
		}

		this._lastCellWithEditorFocus = cell;
	}