TypeScript developer tries Kotlin again

// this is an annotation 
@MongoEntity

// this is a decorator 
@MongoEntity

// This class inherits from ProductBase but the primary constructor must be called, (Kotlin classes have more than 1 constructor) 
class PrivateProduct : ProductBase()

class PrivateProduct inherits ProductBase { constructor() {super()}  }

// the property called 'public' is a Boolean and it is initialised but you can prefix `lateinit` which is equal to the `!` in typescript
val public: Boolean = false

class PrivateProduct inherits ProductBase {
    public readonly public: boolean = false;  
}