if stanConnection == nil || stanConnection.NatsConn() == nil ||  !stanConnection.NatsConn().IsConnected() {
     stanConnection, _ = stan.Connect("test-cluster", "test-client", stan.NatsURL("nats://yourusername:yoursecret@0.0.0.0:4222"), stan.SetConnectionLostHandler(func(c stan.Conn, _ error) {
      if c.NatsConn() != nil {
       c.NatsConn().Close()
      }
      _ = c.Close()
     }))