limit T in a generic class to types that implement some interface

Question

In dart consider the following

class Question<T>{
  String body;
  T answer;
}

//an interface
class IAnswer{
  String Value()=>this.toString();  
}

I need T to be limited to types the for example implement the interface IAnswer, is that possible without having to check if T is IAnswer and throw and exception in the Question constructor?

Answer 1

class Question<T extends IAnswer>{
  String body;
  T answer;
}