Why logstash's redis output plugin send list data with \n?

Using Redis output pluginedit to send data to Redis.

output {
  redis {
    host => ["${REDIS_URL}"]
    data_type => "list"
    key => "ID"
    codec => line { format => "%{[@metadata][_id]}"}
  }
}

Check Redis' data:

LRANGE ID 0 -1
1) "1\n"
2) "2\n"

Why they with \n?

Are you sure that the "\n" isn't coming from your data ?

I have never noticed this myself and I even checked my redis to see if I am getting this and I don't see it