Example:

    ```mlir
    %2 = tfr.call @my_add(%0, %1) : (tfr.tensor, f32) -> tfr.tensor_list
    ```

    Note that the operands of the `call` operation can only be with tfr.tensor,
    tfr.tensor_list, tfr.attr and mlir float and integer types. The results of
    the `call` operation can only be with tfr.tensor and tfr.tensor_list types.
  }];

  let arguments = (ins
    FlatSymbolRefAttr:$callee,

}

// CHECK-LABEL: @tf__fused_n
tfr.func @tf__fused_n(
    %arg0: !tfr.tensor,
    %arg1: !tfr.tensor_list,
    %arg2: index {tfr.name="A",tfr.default=1:index})
  -> !tfr.tensor_list {
  %0 = tfr.call @tf__intermediate(%arg0) : (!tfr.tensor) -> !tfr.tensor
  %1 = tfr.get_element %arg1[%arg2] : (!tfr.tensor_list, index) -> !tfr.tensor
  %2 = tfr.call @tf__intermediate(%1) : (!tfr.tensor) -> !tfr.tensor

  %5 = "tfr.build_list"(%3, %4) : (!tfr.tensor, !tfr.tensor) -> !tfr.tensor_list
  %6 = tfr.quant_raw_data(%5) : (!tfr.tensor_list) -> !tfr.tensor_list
  %7 = "tfr.cast"(%cst_1) : (tensor<i64>) -> !tfr.tensor
  %8 = tfr.call @tf__concat(%7, %6) : (!tfr.tensor, !tfr.tensor_list) -> !tfr.tensor
  func.return %8 : !tfr.tensor

tfr.func @tf__risc_same_(!tfr.tensor<T>) -> !tfr.tensor<T> attributes {T}
tfr.func @tf__risc_concat_(!tfr.tensor_list<N, T>) -> !tfr.tensor<T> attributes {T, N}
tfr.func @tf__risc_split_(!tfr.tensor<T>, i32 {tfr.name="N"}) -> !tfr.tensor_list<N, T> attributes {T, N}
tfr.func @tf__risc_cast_(!tfr.tensor, !tfr.attr {tfr.name="K"}) -> !tfr.tensor<K> attributes {T, K}

  tfr.return %0 : !tfr.tensor
}

tfr.func @tf__my_pack(%values: !tfr.tensor_list,
                      %n: i32 {tfr.name="N"},
                      %axis: i32 {tfr.name="axis"}) -> !tfr.tensor {
  %index = arith.constant 0 : index
  %cst = arith.constant 1 : i32
  %eq = arith.cmpi eq, %n, %cst : i32
  %v1 = tfr.get_element %values[%index] : (!tfr.tensor_list, index) -> !tfr.tensor

constexpr char tfr_raw_text[] = R"(

tfr.func @tf__my_add_n(%values: !tfr.tensor_list,
                       %n: i64 {tfr.name="N"}) -> !tfr.tensor {
  %index = arith.constant 0 : index
  %cst = arith.constant 1 : i64
  %eq = arith.cmpi "eq", %n, %cst : i64
  %v1 = tfr.get_element %values[%index] : (!tfr.tensor_list, index) -> !tfr.tensor
  %res = scf.if %eq -> !tfr.tensor {
    scf.yield %v1 : !tfr.tensor
  } else {

      input_used_attrs.append(used.begin(), used.end());
      continue;
    }

    if (auto tensor_list = arg_type.dyn_cast<TFRTensorListType>()) {
      if (first_tensor_list == -1) {
        first_tensor_list = arg.index();
      }
      last_tensor_list = arg.index();
      auto used = tensor_list.getAttrKeys();
      input_used_attrs.append(used.begin(), used.end());
      continue;
    }

    // Create the new operands. This is mapping the operands from the target
    // TF ops to the TFR function arguments. If the TFR function argument is
    // a tensor_list, a "tfr.build_list" op is used to concat the available
    // TF op operands. If the TFR function argument isn't a tensor/tensor_list,
    // a constant is created by using the attribute stored in the TF op or the
    // default value in the argument attribute.

};

class TFRTensorListType : public detail::TFRTypeImpl<TFRTensorListType> {
 public:
  using TFRBase::TFRBase;
  static constexpr StringLiteral name = "tfr.tensor_list";
  static std::string getTypeName() { return "TFRTensorListType"; }
};

class TFRAttrType : public Type::TypeBase<TFRAttrType, TFRType, TypeStorage> {
 public:
  using Base::Base;

      SmallVector<Value, 4> tensor_list;
      for (int i = res.index(); i < new_op->getNumResults(); i++) {
        Value new_res = new_op->getResult(i);
        auto casted =
            rewriter.create<CastOp>(loc, unconstrainted_type, new_res);
        tensor_list.push_back(casted.getOut());
      }
      auto list_op = rewriter.create<BuildListOp>(loc, res_type, tensor_list);
      new_results.push_back(list_op.getOut());