src/vs/workbench/api/browser/mainThreadNotebookEditors.ts/MainThreadNotebookEditors/handleEditorsAdded
class MainThreadNotebookEditors:	handleEditorsAdded(editors: readonly INotebookEditor[]): void {

		for (const editor of editors) {

			const editorDisposables = new DisposableStore();
			editorDisposables.add(editor.onDidChangeVisibleRanges(() => {
				this._proxy.$acceptEditorPropertiesChanged(editor.getId(), { visibleRanges: { ranges: editor.visibleRanges } });
			}));

			editorDisposables.add(editor.onDidChangeSelection(() => {
				this._proxy.$acceptEditorPropertiesChanged(editor.getId(), { selections: { selections: editor.getSelections() } });
			}));

			const wrapper = new MainThreadNotebook(editor, editorDisposables);
			this._mainThreadEditors.set(editor.getId(), wrapper);
		}
	}