src/vs/workbench/contrib/notebook/browser/notebookKernelServiceImpl.ts/NotebookKernelService/_initSourceActions
class NotebookKernelService:	private _initSourceActions() {
		const loadActionsFromMenu = (menu: IMenu) => {
			const groups = menu.getActions({ shouldForwardArgs: true });
			const actions: IAction[] = [];
			groups.forEach(group => {
				actions.push(...group[1]);
			});
			this._sourceActions = actions.map(action => {
				const sourceAction = new SourceAction(action);
				const stateChangeListener = sourceAction.onDidChangeState(() => {
					this._onDidChangeSourceActions.fire();
				});
				return [sourceAction, stateChangeListener];
			});
			this._onDidChangeSourceActions.fire();
		};

		this._register(this._sourceMenu.onDidChange(() => {
			loadActionsFromMenu(this._sourceMenu);
		}));

		loadActionsFromMenu(this._sourceMenu);
	}