@startuml
'fig_4'
left to right direction
skinparam monochrome true
skinparam handwritten false
hide class circle
skinparam shadowing false
skinparam classAttributeIconSize 0
hide methods

class Apple {
+ color: str
+ weight: float
+ barrel: Barrel
}
class Barrel {
+ size: int
+ apples: List[Apple]
}
Apple "*" --- "1"  Barrel : go in >

class Orange {
+ weight: float
+ orchard: str
+ date_picked: date
+ basket: Basket
}
class Basket {
+ location: str
+ oranges: List[Orange}
}
Orange "*" --- "1" Basket : go in >


@enduml
