code: @NonNull
    public final GenericType<T> unwrap() {
      if (Primitives.allWrapperTypes().contains(token.getRawType())) {
        return new GenericType<>(token.unwrap());
      }
      return this;
    }
docs: Returns the corresponding primitive type if this is a wrapper type; otherwise returns {@code
  this} itself. Idempotent.