Containers are easily implemented with events.
Say you want a container with 2 objects: Sprite* and Sprite2
* Sprite will be the primary object of the container. If you want to destroy or create the container destroy/create Sprite.
//first all container objects are created for each Sprite
+On start of layout
--- Sprite2: destroy
--- Sprite: spawn Sprite2
//creating a container
+Sprite: on created
--- Sprite: spawn Sprite2
//destroying a container
+Sprite: on destroyed
+System: pick Sprite2 instance Sprite.IID
--- Sprite2: destroy
//Then for simple container picking
+every tick
--- Sprite2: set position to Sprite
//Or when you want to pick the contained objects after some other picking has been done:
+for each Sprite
+System: pick Sprite2 instance Sprite.IID
--- Sprite2: set position to Sprite