src/vs/workbench/api/common/extHostNotebookEditor.ts/NotebookEditorCellEditBuilder/finalize
class NotebookEditorCellEditBuilder:	finalize(): INotebookEditData {
		this._finalized = true;
		return {
			documentVersionId: this._documentVersionId,
			cellEdits: this._collectedEdits
		};
	}