[REQ] generic return type for method chaining

Is your feature request related to a problem? Please describe.

When I define a property "foo" on base type "Animal" and then create an instance of subtype "Dog", I can call dog.foo("value") but it returns the object as an Animal. Now I can't chain other properties of any subtypes.

Describe the solution you'd like

Return the object as the actual type.
At least add an override with a simple call to super.foo() and a type cast. That should be enough for most use cases.

Or make it like this in the base type (Java example):

public <T extends Animal> T foo(String foo){
  this.foo=foo;
  return (T)this;
}

And if T is actually a generic type parameter of the baseclass (i.e. Animal<T extends Animal>) it just works because T is always the correct type.

Describe alternatives you've considered

I didn't find any solution other than not using a discriminator and them ending up with no inheritence.

Additional context

Maybe there is a better solution. I didn't find anything on creating a builder instead or something else that handles this problem.

Start by tracing how Java models with inheritance and discriminators are generated, using the Animal, Dog, and foo example from the issue as the target case. Compare fluent setter return types with the proposed generic-base-type and override alternatives; done means a selected approach is defined and its generated output and compatibility implications are covered by tests.