@startuml

scale 800*800

class Singleton{
    -INSTANCE
    -Singleton()
    +getInstance()
}

note right of Singleton
  ...
  <color:red>(1)</color>private static final Singleton INSTANCE = new Singleton();
  <color:red>(2)</color>private Singleton(){}
  <color:red>(3)</color>public static Singleton getInstance(){
        return INSTANCE;
  }...

  <color:red>(1)</color> = INSTANCE 常數
  <color:red>(2)</color> = 私有建構函式
  <color:red>(3)</color> = 靜態方法
end note

@enduml