Class Animal
EndClass

Class Dog Extends Animal
  Public Method Bark()
  EndMethod
EndClass

Class Cat Extends Animal
  Public Method Sleep()
  EndMethod
EndClass

Class Lab Extends Dog
  Public Method Swim()
  EndMethod
EndClass

Class Collie Extends Dog
  Public Method Fetch()
  EndMethod
EndClass

;- test the code
*Lassie.Collie = NewObject.Collie
*Lassie\Bark()
*Lassie\Fetch()