PlantUML — Object Diagram

@startuml
object alice {
  id = 1
  name = "Alice"
  email = "alice@acme.co"
}
object order42 {
  id = 42
  total = 199.00
  status = "PAID"
}
object item1 {
  sku = "BK-001"
  qty = 2
}
alice --> order42 : places
order42 --> item1 : contains
@enduml