Core lib with AssetType Any, Undefined and ContainableByAny
the core.abs should contain a root type and commonly used type
I suggest
abstract AssetType Any {
}
abstract AssetType ContainableByAny {
description "AssetType subtyping this can be contained by any other Assets, usable for free drawing"
container reference containedBy : Any
}
AssetType Undefined {
}
where Undefined
can be used by editor to simplify the asset creation (by Sirius for example)