Mermaid UML diagrams

classDiagram
    Animal <|-- Duck
    Animal <|-- Fish
    Animal <|-- Zebra
    Animal : +int age
    Animal : +String gender
    Animal: +isMammal()
    Animal: +mate()

class Duck{
        +String beakColor
        +swim()
        +quack()
    }

class Fish{
        -int sizeInFeet
        -canEat()
    }

class Zebra{
        +bool is_wild
        +run()
    }

print("hello world")