How to use the datx.Model function in datx

private __addRecord(obj: IRecord): IJsonapiModel {
      const staticCollection = this.constructor as typeof Collection;
      const {type, id} = obj;
      let record: IJsonapiModel = this.find(type, id) as IJsonapiModel;
      const flattened: IRawModel = flattenModel(obj);

      if (record) {
        updateModel(record, flattened);
      } else if (staticCollection.types.filter((item) => item.type === obj.type).length) {
        record = this.add(flattened, obj.type) as IJsonapiModel;
      } else {
        record = this.add(new Model(flattened));
      }

      return record;
    }