Add EntityCollection

src/main/kotlin/fr/postgresjson/entity/Entity.kt

@@ -6,7 +6,7 @@ interface EntityI<T> {
     var id: T
 }
 abstract class Entity<T>(override var id: T) : EntityI<T>
-abstract class UuidEntity(override var id: UUID = UUID.randomUUID()) : Entity<UUID>(id) {}
+abstract class UuidEntity(override var id: UUID = UUID.randomUUID()) : Entity<UUID>(id)
 abstract class IdEntity(override var id: Int) : Entity<Int>(id)
 
 interface EntityVersioning<T> {

src/main/kotlin/fr/postgresjson/entity/EntityCollection.kt

@@ -0,0 +1,13 @@
+package fr.postgresjson.entity
+
+class EntityCollection<T, E : EntityI<T>> {
+    var collection: MutableMap<T, E> = mutableMapOf()
+
+    fun get(id: T): E? {
+        return collection[id]
+    }
+
+    fun set(entity: E) {
+        collection.set(entity.id, entity)
+    }
+}