Is it possible to group participants in PlantUML?

Question

I want to have a box around a couple of participants showing that they are part of an entity. How can you do this in PlantUML?

Disposure

Answer 1

You can "box" participants as shown on plantuml site (extract below)

@startuml

box "Internal Service" #LightBlue
participant Bob
participant Alice
end box
participant Other

Bob -> Alice : hello
Alice -> Other : hello

@enduml

This produces:

Shakedown