I need to use explicit bidirectional aggregation and composition ( https://pasteboard.co/2Ui6pbkek.png
However I had no luck to find it in the documentation. I tried to use A *<--> B and C <*--> D but they do not work.
I also miss the unidirectional to aggregation/composition ( https://pasteboard.co/2VunFvLqw.png
Is this feature supported?