从RethinkDB changefeed获取空结构:)

I am using Golang + RethinkDB (Gorethnkdb v.5). I'm subscribing for changes in a "posts" table. And It works on a half: I prints on changes (means it actually works on detecting changes) but structs are empty after all :(

{"Id":"","IP":"","TS":0,"auth":"","body":"","check":"","Status":""} 

Here is my code.

func WatchPosts() {
    cursor, err := r.Table("posts").Changes().Run(Session)
    if err != nil {
        fmt.Println(err)
    }

    var post Post

    for cursor.Next(&post) {
        data, err := json.Marshal(post)
        if err != nil {
            panic(err)
        }
        fmt.Println(string(data))
    }

}

I want to receive structs with data. How should I fix it. Please help me. Thanks in advance