Main components are Entitiy, Port, Relation and Link
they have a name by the NamedObject abstract class
they can be annotated by arbitrary data through the Annotatableabstract class.
Annotations can be subclassed by anybody in order to allow arbitrary piggyback data on entities. This is similar to the Property resp. Attribute mechanism in Ptolemy II, Annotations in SCADE or EAnnotations in Ecore (the StringAnnotation is just an Example).
Common use cases for such attributes are
store layout information (layout options)
store semantic detail information (e.g. properties of actors)
Entities can contain other entities to get hierarchy and contain Port, Relation and Link objects.
Connections are established between Linkableswhich are mainly Ports and Relations (close to Ptolemy II)
Links are real objects in the model, corresponding to edges in the graphical representation (different to Ptolemy II)
Relations are used as in Ptolemy II to form hyperedges where multiple ports are interconnected. However, here a simple link between two ports does not require a Relation.
State is a special kind of an Entity which is also a Linkable and hence can be directly connected without a port.
Actor is not a Linkable and hence needs ports to be connected to something.
