It used to work but now returns an empty set, am I doing something wrong or is there some other way to get them?
IntelliJ plugin needs it:
https://github.com/esteinberg/plantuml4idea/blob/11aec1eedd4977acaddfeafb859b558e49d733b4/src/org/plantuml/idea/plantuml/PlantUmlIncludes.java#L29-L30
main.puml:
@startuml !include external.puml A --> B : a @enduml
external.puml:
@startuml Alice -> Bob: Authentication Request Bob --> Alice: Authentication Response @enduml
(--------)