@startuml usecase-sample
!includeurl https://diamondbc.github.io/uml/core.puml
' uncomment the following line and comment the first to use locally
'!include core.puml

' 设置方向
LAYOUT_LEFT_RIGHT
'LAYOUT_TOP_DOWN
'LAYOUT_AS_SKETCH


actor customer
actor clerk

UserCasePackage("checkout","买单") {
    customer -- (checkout)
    (checkout) .> (payment) : include
    (help) .> (checkout) : extends
    (checkout) -- clerk
}

@enduml



