To get you started, you can create a small "constructor" function that returns new instances. Try this:
typedef BaseType Builder();
class Cloner {
Builder builder;
Cloner(Builder builder);
BaseType getAnother() {
BaseType newthing = builder();
newthing.callsomeBaseTypeMethod();
return newthing;
}
}
main() {
var cloner = new Cloner(() => new BaseType());
var thing = cloner.getAnother();
}
In the above code, we create a typedef to define a function that returns a BaseType.