Needs implemented in annotations:

(01:33:33 PM) gbadner: in the metamodel, an @Embeddable attribute is modeled as a CompositeAttributeBinding
(01:34:31 PM) gbadner: Address is is modeled with an actual CompositeAttributeBinding
(01:35:26 PM) gbadner: List<Address> addresses; the List part is the attribute binding (PluralAttributeBinding)
(01:36:13 PM) gbadner: in this case, Address is not an attribute binding; it's the collection element
(01:36:55 PM) gbadner: so, Address is modeled as a CompositeAttributeBindingContainer
(01:37:27 PM) gbadner: iow, it's a container for AttributeBinding objects that is "aggregated" into an Address
(01:38:13 PM) gbadner: it is an AttributeBindingContainer, not an AttributeBinding
(01:38:36 PM) gbadner: CompositeAttributeBindingContainer extends AttributeBindingContainer
(01:40:25 PM) gbadner: Address address; modeled as a CompositeAttributeBinding (which implements CompositeAttributeBindingContainer); CompositeAttributeBinding IS an AttributeBinding as well as a container for AttributeBinding objects
(01:41:30 PM) gbadner: really, the only thing you should need to do at this point is to implement CompositePluralAttributeElementSource for annotations
(01:42:07 PM) gbadner: e.g., create o.h.metamodel.internal.source.annotations.CompositePluralAttributeElementSourceImpl
(01:44:02 PM) gbadner: you'll see that there is already BasicPluralAttributeElementSourceImpl for annotations; that's for BASIC collection elements (e.g., for String elements in List<String>)
(01:45:35 PM) gbadner: you'll need to hook CompositeAttributeBindingContainerImpl up into o.h.metamodel.internal.source.annotations.PluralAttributeSourceImpl.determineElementSource() for the ELEMENT_COLLECTION_EMBEDDABLE case