Void/Unit subscripable

src/main/kotlin/ru/dbotthepony/mc/otm/core/ISubscripable.kt

@@ -66,6 +66,44 @@ interface ISubscriptable<V> {
 	}
 }
 
+interface IUnitSubscripable : ISubscriptable<Unit> {
+	fun addListener(listener: Runnable): ISubscriptable.L
+
+	override fun addListener(listener: Consumer<Unit>): ISubscriptable.L {
+		return addListener(Runnable { listener.accept(Unit) })
+	}
+
+	class Impl : IUnitSubscripable, Runnable {
+		private inner class L(val callback: Runnable) : ISubscriptable.L {
+			private var isRemoved = false
+
+			init {
+				subscribers.add(this)
+			}
+
+			override fun remove() {
+				if (!isRemoved) {
+					isRemoved = true
+					queue.add(this)
+				}
+			}
+		}
+
+		private val subscribers = ReferenceLinkedOpenHashSet<L>(0)
+		private val queue = ReferenceArraySet<L>(0)
+
+		override fun addListener(listener: Runnable): ISubscriptable.L {
+			return L(listener)
+		}
+
+		override fun run() {
+			queue.forEach { subscribers.remove(it) }
+			queue.clear()
+			subscribers.forEach { it.callback.run() }
+		}
+	}
+}
+
 interface IFloatSubcripable : ISubscriptable<Float> {
 	@Deprecated("Use type specific listener")
 	override fun addListener(listener: Consumer<Float>): ISubscriptable.L {