src/vs/workbench/api/common/extHostNotebookEditor.ts/NotebookEditorCellEditBuilder/replaceCellMetadata
class NotebookEditorCellEditBuilder:	replaceCellMetadata(index: number, metadata: Record<string, any>): void {
		this._throwIfFinalized();
		this._collectedEdits.push({
			editType: CellEditType.PartialMetadata,
			index,
			metadata
		});
	}