@startuml

scale 3.0

actor "<u>:Cashier" as C
participant "<u>:Register" as R
participant "<u>:Sale" as S
collections "<u>:SalesLineItem" as SLI

C -> R ++ : makeNewSale()

autonumber

R -> S ** : create()
activate S

S -> SLI ** : create() 

@enduml