@startuml

actor UR as "UN researcher"

rectangle Database

rectangle "Create a report of countries in (N)" {
    usecase UCG as "Get countries in (N)"
    usecase UCa as "Select continent (N)"
    usecase UCb as "Create report"

    UR - UCG
    UCG <.. UCa : extend
    UCa ..> UCb : include
    UCG - Database
}

@enduml