Android 工作室一直告诉我工厂 class 需要 body,有什么问题吗?

Android studio keeps telling me that the factory class needs a body, what could be wrong?

class WallpaperModel{

  late String photographer;
  late String photographer_url;
  late int photographer_id;
  SrcModel src;

  WallpaperModel({ required this.src, required this.photographer_url,required this.photographer_id, required this.photographer})

  factory WallpaperModel.fromMap(Map<String,dynamic> jsonData){
    return WallpaperModel(src: jsonData['src'],
        photographer_url: jsonData['photographer_url'],
        photographer_id: jsonData['photographer_id'],
        photographer: jsonData['photographer']);
  }
}

我正在尝试将 Pexels API 实施到壁纸应用程序中,但 Android 工作室将工厂 class 标记为需要 body 的错误。可能出了什么问题?

问题是此行缺少分号 ;

  WallpaperModel({ required this.src, required this.photographer_url,required this.photographer_id, required this.photographer});