attr_cst =
              builder.create<ConstOp>(op->getLoc(), output_type, attribute);
        } else {
          attr_cst = builder.create<mlir::arith::ConstantOp>(
              op->getLoc(), cast<TypedAttr>(attribute));
        }
        new_operands.push_back(attr_cst);
      }
    }

    // Create the TFR call op
    auto new_op = builder.create<CallOp>(

    std::string tmp_dir{};
    if (!env_->LocalTempFilename(&tmp_dir)) {
      return absl::InternalError("Failed to create temp file.");
    }

    TF_CHECK_OK(env_->CreateDir(tmp_dir));
    return tmp_dir;
  }

  // Parses `module_op_str` to create a `ModuleOp`. Checks whether the created
  // module op is valid.
  mlir::OwningOpRef<mlir::ModuleOp> ParseModuleOpString(
      const absl::string_view module_op_str) {

  TF_Output output{dequeue_op, 0};
  TF_Tensor* ret;
  TF_SessionRun(session, /*run_options*/ nullptr,
                // input related parameters
                /*inputs*/ nullptr, /*input_values*/ nullptr, /*ninputs*/ 0,
                // output related parameters
                /*outputs*/ &output, /*output_values*/ &ret,
                /*noutputs*/ 1,
                /*targets*/ nullptr, /*ntargets*/ 0,

  // (a) read-only. These reads can be replaced by a hoisted read created
  //        before the WhileOp (similar to if and case).
  // (b) written: since the value is written in the loop (which can only in
  //        loop body, all these will become loop variables. Since all resource
  //        variables are removed from the loop variabled during
  //        canonicalizationW, we need to create new operand/result slots. The

}

// This is a basic test to make sure the C++ gradient code can handle while
// loops created by the C API (which calls the C++ API under the hood). There
// are more while loop gradient tests in cc/framework/while_gradients_test.cc.
TEST_F(CApiWhileLoopTest, Gradients) {
  Init(1);

  // Create loop: while (i < 10) i += 1
  TF_Operation* ten = ScalarConst(10, params_->cond_graph, s_);
  TF_Operation* less_than =

  if (only_one_return_value) {
    return_types.resize(1);
  }

  auto type = FunctionType::get(region.getContext(), input_types, return_types);

  // Create new function and extract region body into the function.
  auto outlined_func = builder.create<func::FuncOp>(loc, name, type);
  Region& func_region = outlined_func.getBody();
  func_region.takeBody(region);
  Block& first_block = func_region.front();

      // Create new ConstantOp-Dequantize-Operation sequences. At this moment,
      // old ConstantOp is guaranteed to have one F32->F16 cast regardless of
      // its number of users.
      rewriter.setInsertionPointAfter(op);
      auto new_const = rewriter.create<arith::ConstantOp>(
          op->getLoc(), new_result_type, new_value_attr);
      auto dq = rewriter.create<DQ>(op->getLoc(), old_result_type, new_const);

    func::FuncOp parent_func, ModuleOp module, const std::string& name) {
  // Moves all of the Operations in 'ops' into a newly created func.FuncOp
  // function named 'name' and replaces the original ops with a call to the
  // newly created function using a tf.StatefulPartitionedCall. Here,
  // 'parent_func' is the function that holds the original set of ops.

  }

  SmallVector<Value> return_values;
  for (Value result : results) {
    return_values.push_back(mapping.lookupOrNull(result));
  }
  builder.create<func::ReturnOp>(location, return_values);

  // Create a function call to the newly created function.
  StringAttr new_func_name =
      InsertToSymbolTable(*module, *wrap_func, func_name);
  builder.setInsertionPointAfter(result_op);
  ValueRange new_results =

  if (subtypes.size() != 1) {
    return std::nullopt;
  }
  return subtypes[0].getElementType();
}

// Create an `ConstBytesAttr` which encodes the options
// for the `tf.custom` tensor list op to be created. If the given
// op is not a `tf.TensorList*` op, return empty, although this case
// should never be trigged in practice since patterns are only applied
// on `tf.TensorList*` ops.