@startuml

scale 3
hide circle

class Store {
    address: Address
    name: Text    
    addSale()
}

class Register {
    makeNewSale()
    enterItem()
    endSale()
    makePayment()
}

class ProductCatalog {
    getSpecification(itemID): ProductSpecification
}

class ProductSpecification {
    description: Text
    price: Money
    itemID: itemID
}

class Sale {
    date: Date
    isComplete: Boolean
    time: Time
    
    becomeComplete()
    makeLineItem()
    makePayment()
    getTotal()
}

class SalesLineItem {
    quantity: Integer
    getSubtotal(): Money
}

class Payment {
    amount: Money
}

Store -r-> ProductCatalog : uses
Store -d-> Register: houses
Store -d-> Sale: logs-completed

Register -u-> ProductCatalog: looks-in
Register -r-> Sale : captures

ProductCatalog -r-> "1..*" ProductSpecification: contains

Sale -r-> "1..*" SalesLineItem: contains
Sale "1" -r--> "1" Payment

SalesLineItem "*" -u-> "1" ProductSpecification: described-by

Register .u.> ProductSpecification
Sale .u.> ProductSpecification

@enduml