Add Prototype pattern

[babedev]

Demonstrate how to implement Prototype pattern in Kotlin

[jolkdarr]

A very simple example:

abstract class Prototype : Cloneable { public override fun clone() = super.clone() as Prototype } class ConcretePrototype1 : Prototype() { public override fun clone() = super.clone() as ConcretePrototype1 } object ConcretePrototype2 : Prototype() { public override fun clone() = super.clone() as ConcretePrototype2 } fun main() { val prototype1 = ConcretePrototype1() println(prototype1.clone()) println(prototype1.clone().clone()) println(ConcretePrototype2.clone()) println(ConcretePrototype2.clone()) }

with the output:

ConcretePrototype1@24d46ca6 ConcretePrototype1@4517d9a3 ConcretePrototype2@372f7a8d ConcretePrototype2@2f92e0f4 

It shows two prototypes: one classic class instance and one object.
In the sample, a clone object is also a prototype.
Objects may be declared in scala or kotlin, but not yet in java.