docs: function hsetnx(key, field, value, req) {
    var val = this.getKey(key, req)
      , exists = this.hexists(key, field, req);
    if(!val) {
      val = new HashMap();
      this.setKey(key, val, undefined, undefined, undefined, req);
    }
    if(!exists) {
      // set on the hashmap
      val.setKey(field, value);
    }
    return exists ? 0 : 1;
  }