defer sl.Stop()

	select {
	case <-sl.C:
	case <-ctx.Done():
		return ctx.Err()
	}

	return nil
}

func TestCacheCtx(t *testing.T) {
	cache := New[time.Time]()
	t.Parallel()
	cache.InitOnce(2*time.Second, Opts{},
		func(ctx context.Context) (time.Time, error) {
			return time.Now(), slowCaller(ctx)
		},
	)

	ctx, cancel := context.WithCancel(context.Background())
	cancel() // cancel context to test.

	return &Cache[T]{
		ttl:      ttl,
		updateFn: update,
		opts:     opts,
	}
}

// InitOnce initializes the cache with a TTL and an update function. It is
// guaranteed to be called only once.
func (t *Cache[T]) InitOnce(ttl time.Duration, opts Opts, update func(ctx context.Context) (T, error)) {
	t.Once.Do(func() {
		t.ttl = ttl
		t.updateFn = update
		t.opts = opts
	})

	}
	if n.QueueDir != "" {
		if !filepath.IsAbs(n.QueueDir) {
			return errors.New("queueDir path should be absolute")
		}
	}

	return nil
}

// NSQTarget - NSQ target.
type NSQTarget struct {
	initOnce once.Init

	id         event.TargetID
	args       NSQArgs
	producer   *nsq.Producer
	store      store.Store[event.Event]
	config     *nsq.Config
	loggerOnce logger.LogOnce
	quitCh     chan struct{}
}

		return errors.New("cert and key must be specified as a pair")
	}
	return nil
}

// WebhookTarget - Webhook target.
type WebhookTarget struct {
	initOnce once.Init

	id         event.TargetID
	args       WebhookArgs
	transport  *http.Transport
	httpClient *http.Client
	store      store.Store[event.Event]
	loggerOnce logger.LogOnce

			return fmt.Errorf("expected type %v does not match with available type %v", expectedType, typeAvailable)
		}
	}

	return nil
}

// RedisTarget - Redis target.
type RedisTarget struct {
	initOnce once.Init

	id         event.TargetID
	args       RedisArgs
	pool       *redis.Pool
	store      store.Store[event.Event]
	firstPing  bool
	loggerOnce logger.LogOnce
	quitCh     chan struct{}
}

		if !filepath.IsAbs(a.QueueDir) {
			return errors.New("queueDir path should be absolute")
		}
	}

	return nil
}

// AMQPTarget - AMQP target
type AMQPTarget struct {
	initOnce once.Init

	id         event.TargetID
	args       AMQPArgs
	conn       *amqp091.Connection
	connMutex  sync.Mutex
	store      store.Store[event.Event]
	loggerOnce logger.LogOnce

			return errors.New("batch commit timeout should be set only if queue dir is enabled and batch size > 1")
		}
	}
	return nil
}

// KafkaTarget - Kafka target.
type KafkaTarget struct {
	initOnce once.Init

	id         event.TargetID
	args       KafkaArgs
	client     sarama.Client
	producer   sarama.SyncProducer
	config     *sarama.Config
	store      store.Store[event.Event]

	if p.MaxOpenConnections < 0 {
		return errors.New("maxOpenConnections cannot be less than zero")
	}

	return nil
}

// PostgreSQLTarget - PostgreSQL target.
type PostgreSQLTarget struct {
	initOnce once.Init

	id         event.TargetID
	args       PostgreSQLArgs
	updateStmt *sql.Stmt
	deleteStmt *sql.Stmt
	insertStmt *sql.Stmt
	db         *sql.DB
	store      store.Store[event.Event]

		}
		if m.QoS == 0 {
			return errors.New("qos should be set to 1 or 2 if queueDir is set")
		}
	}

	return nil
}

// MQTTTarget - MQTT target.
type MQTTTarget struct {
	initOnce once.Init

	id         event.TargetID
	args       MQTTArgs
	client     mqtt.Client
	store      store.Store[event.Event]
	quitCh     chan struct{}
	loggerOnce logger.LogOnce
}

				return
			}
			sizeS.totalSize = s.Size()
			sizeS.versions++
			return sizeS, nil
		}
		return
	}
	xls := xlStorage{drivePath: base, diskInfoCache: cachevalue.New[DiskInfo]()}
	xls.diskInfoCache.InitOnce(time.Second, cachevalue.Opts{}, func(ctx context.Context) (DiskInfo, error) {
		return DiskInfo{Total: 1 << 40, Free: 1 << 40}, nil
	})
	weSleep := func() bool { return false }