return Type();
    });
    addConversion([](stablehlo::TokenType token) {
      return vhlo::TokenV1Type::get(token.getContext());
    });
    addBuiltinToVhloConversions();

    addArgumentMaterialization(MaterializeIllegalCast);
    addSourceMaterialization(MaterializeIllegalCast);
    addTargetMaterialization(MaterializeIllegalCast);
  }

  Attribute convertEncoding(Attribute attr) const final {