How to get the class name generic interface

Question

public interface Transformer<I, O> {
    O transform(I var1);
}

class Test{
  @Autowired
  // The purpose of this transformer is to convert java object to 
  ion formatted string
  private Transformer<Car,String> serialize;

  public void fun(){
   Car c = new Car();
   c.setName("Audi");
   String ion = serialize.transform(c);
  }
}

Transformer interface is getting implemented by some class containing the logic for transformation . I need to know the class name of the generic params passed in while initialising the variable.