src/vs/workbench/api/browser/mainThreadNotebookDocumentsAndEditors.ts/MainThreadNotebooksAndEditors/_isDeltaEmpty
class MainThreadNotebooksAndEditors:	private static _isDeltaEmpty(delta: INotebookAndEditorDelta): boolean {
		if (delta.addedDocuments !== undefined && delta.addedDocuments.length > 0) {
			return false;
		}
		if (delta.removedDocuments !== undefined && delta.removedDocuments.length > 0) {
			return false;
		}
		if (delta.addedEditors !== undefined && delta.addedEditors.length > 0) {
			return false;
		}
		if (delta.removedEditors !== undefined && delta.removedEditors.length > 0) {
			return false;
		}
		if (delta.visibleEditors !== undefined && delta.visibleEditors.length > 0) {
			return false;
		}
		if (delta.newActiveEditor !== undefined) {
			return false;
		}
		return true;
	}