#590 Add new presentation for Singleton

singleton/etc/singleton.urm.puml

@@ -1,43 +0,0 @@
-@startuml
-package com.iluwatar.singleton {
-  class App {
-    - LOGGER : Logger {static}
-    + App()
-    + main(args : String[]) {static}
-  }
-  enum EnumIvoryTower {
-    + INSTANCE {static}
-    + toString() : String
-    + valueOf(name : String) : EnumIvoryTower {static}
-    + values() : EnumIvoryTower[] {static}
-  }
-  class InitializingOnDemandHolderIdiom {
-    - InitializingOnDemandHolderIdiom()
-    + getInstance() : InitializingOnDemandHolderIdiom {static}
-  }
-  -class HelperHolder {
-    - INSTANCE : InitializingOnDemandHolderIdiom {static}
-    - HelperHolder()
-  }
-  class IvoryTower {
-    - INSTANCE : IvoryTower {static}
-    - IvoryTower()
-    + getInstance() : IvoryTower {static}
-  }
-  class ThreadSafeDoubleCheckLocking {
-    - instance : ThreadSafeDoubleCheckLocking {static}
-    - ThreadSafeDoubleCheckLocking()
-    + getInstance() : ThreadSafeDoubleCheckLocking {static}
-  }
-  class ThreadSafeLazyLoadedIvoryTower {
-    - instance : ThreadSafeLazyLoadedIvoryTower {static}
-    - ThreadSafeLazyLoadedIvoryTower()
-    + getInstance() : ThreadSafeLazyLoadedIvoryTower {static}
-  }
-}
-IvoryTower -->  "-INSTANCE" IvoryTower
-ThreadSafeDoubleCheckLocking -->  "-instance" ThreadSafeDoubleCheckLocking
-ThreadSafeLazyLoadedIvoryTower -->  "-instance" ThreadSafeLazyLoadedIvoryTower
-HelperHolder ..+ InitializingOnDemandHolderIdiom
-HelperHolder -->  "-INSTANCE" InitializingOnDemandHolderIdiom
-@enduml