Is it possible to have the text of an arrow parallel to the arrow and ontop of it?
In particular, I'd like to make an use-case diagram with extend/include arrows looking like this:

As you can see, the <<extend>> and <<include>> are part of the arrow.
If I try to recreate the same in PlantUML, it looks like this:

@startuml
usecase "UseCase" as a
usecase "UseCase" as b
usecase "UseCase" as c
a -[hidden]r-> c
a .d.> b : <<extend>>
b <.u. c : <<include>>
@enduml
Is there a way to achieve the wanted look in PlantUML?
Thank you for your help.