add: } else if (thread->debug_info.flags & B_THREAD_DEBUG_NUB_THREAD) {  error = B_NOT_ALLOWED;
context: _user_debug_thread(thread_id threadID){	// tell the thread to stop as soon as possible	status_t error = B_OK;	cpu_status state = disable_interrupts();	GRAB_THREAD_LOCK();	struct thread *thread = thread_get_thread_struct_locked(threadID);	if (!thread) {		// thread doesn't exist any longer		error = B_BAD_THREAD_ID;	} else if (thread->team == team_get_kernel_team()) {		// we can't debug the kernel team		error = B_NOT_ALLOWED;	} else if (thread->debug_info.flags & B_THREAD_DEBUG_DYING) {		// the thread is already dying -- too late to debug it		error = B_BAD_THREAD_ID;	} else if (!(thread->debug_info.flags & B_THREAD_DEBUG_STOPPED)) {		// set the flag that tells the thread to stop as soon as possible		atomic_or(&thread->debug_info.flags, B_THREAD_DEBUG_STOP);		switch (thread->state) {			case B_THREAD_SUSPENDED:				// thread suspended: wake it up				thread->state = thread->next_state = B_THREAD_READY;				scheduler_enqueue_in_run_queue(thread);				break;			case B_THREAD_WAITING:				// thread waiting: interrupt it				sem_interrupt_thread(thread);				break;		}	}	RELEASE_THREAD_LOCK();	restore_interrupts(state);	return error;}