must be of arity == 2
(edgeCompanion: StringAdd).self
(edgeCompanion: StringFormat).self
(edgeCompanion: ArrowAssoc[EdgeCompanion[E]]).x
(Since version 2.10.0) Use leftOfArrow
instead
(edgeCompanion: Ensuring[EdgeCompanion[E]]).x
(Since version 2.10.0) Use resultOfEnsuring
instead
The abstract methods of this trait must be implemented by companion objects of simple (non-weighted, non-labeled) edges.