src/vs/workbench/api/browser/mainThreadNotebookDocumentsAndEditors.ts/NotebookAndEditorState/constructor
class NotebookAndEditorState:	constructor(
		readonly documents: Set<NotebookTextModel>,
		readonly textEditors: Map<string, IActiveNotebookEditor>,
		readonly activeEditor: string | null | undefined,
		readonly visibleEditors: Map<string, IActiveNotebookEditor>
	) {
		//
	}