Flutter/dart/singleton

class SingletonHoge {
  SingletonHoge._privateConstructor();
  static final SingletonHoge _instance = SingletonHoge._privateConstructor();
  static SingletonHoge get instance {
    return _instance;
  }
}

SingletonHoge hoge = SingletonHoge.instance;

https://stackoverflow.com/questions/12649573/how-do-you-build-a-singleton-in-dart