src/vs/workbench/contrib/debug/common/debugLifecycle.ts/DebugLifecycle/shouldVetoShutdown
class DebugLifecycle:	private shouldVetoShutdown(_reason: ShutdownReason): boolean | Promise<boolean> {
		const rootSessions = this.debugService.getModel().getSessions().filter(s => s.parentSession === undefined);
		if (rootSessions.length === 0) {
			return false;
		}

		const shouldConfirmOnExit = this.configurationService.getValue<IDebugConfiguration>('debug').confirmOnExit;
		if (shouldConfirmOnExit === 'never') {
			return false;
		}

		return this.showWindowCloseConfirmation(rootSessions.length);
	}