 /// Entity can be seen as a bag of components. 
 /// It is managed by a context and also created by a context instance.
 /// For querying a group of entites please have a look at Group class.
-/// You can observer entity changes by implementing EntityChangedListener protocol.
+/// You can observe entity changes by implementing EntityChangedListener protocol.
 public final class Entity {
     private var _components : [ComponentId:Component]
     private var observers : [EntityChangedListener]



// _EntityChangedListener is introduced to be an internal access protocol which Context implements.
// We avoid EntityChangedListener as it is public and therefor would pollute Context API.
protocol _EntityChangedListener : class {
    func componentAdded(entity: Entity, component: Component)
    func componentRemoved(entity: Entity, component: Component)

        }
        changedComponents.removeAll(keepCapacity: false)
    }
}
