// Invoke the original method:
                        Type[] argumentTypes = Type.getArgumentTypes(methodData.descriptor);
                        for (int argIndex = 1; argIndex <= argumentTypes.length; ++argIndex) {
                            visitVarInsn(argumentTypes[argIndex - 1].getOpcode(Opcodes.ILOAD), argIndex);
                        }

        val typeParameterSymbols = symbol.typeParameterSymbols ?: return superTypes.asSequence()
        val argumentTypes = (session.typeContext.captureArguments(this, CaptureStatus.FROM_EXPRESSION)?.toList()
            ?: this.typeArguments.mapNotNull { it.type })

        require(typeParameterSymbols.size == argumentTypes.size) {
            val renderedSymbol = FirRenderer.noAnnotationBodiesAccessorAndArguments().renderElementAsString(symbol.fir)

        Type returnType = Type.getReturnType(standardDescriptor);
        Type[] argumentTypes = Type.getArgumentTypes(standardDescriptor);
        Type[] argumentTypesWithDefault = Stream.concat(
            Arrays.stream(argumentTypes),
            Stream.of(Type.getType(int.class), Type.getType(Object.class))
        ).toArray(Type[]::new);

    }
  }

  // Remove unread var handle arguments.
  for (int argument_index_to_remove :
       llvm::reverse(argument_indices_to_remove)) {
    block.eraseArgument(argument_index_to_remove);
    argument_types.erase(argument_types.begin() + argument_index_to_remove);
  }

  // Rewrite return if there are variable writes.
  const int return_operands_size = return_operands.size();
  if (return_operands_size > num_results_before) {

    std::vector<Type> argument_types;
    for (auto arg : f.getBody().front().getArguments()) {
      argument_types.push_back(arg.getType());
    }
    std::vector<Type> return_types;
    for (auto ret_op : ret->getOperands()) {
      return_types.push_back(ret_op.getType());
    }
    auto newType =
        FunctionType::get(rewriter.getContext(), argument_types, return_types);

  }
}

// Updates 'while_op' signatures based on which arguments should be removed
// in 'arguments_to_erase'.
template <typename T, typename U>
T GetUpdatedWhileOp(T while_op, const U& argument_types,
                    const llvm::SmallVector<unsigned, 4>& arguments_to_erase) {
  OpBuilder builder(while_op);
  llvm::SmallVector<Type, 4> new_operand_types;
  llvm::SmallVector<Value> new_operands;

void RuntimeFallbackExecutor::RunTfrtInitializer() {
  const Function* func = bef_file_->GetFunction("_tfrt_fallback_init");
  CHECK(func) << "TFRT initialization function was not found";
  CHECK_EQ(func->argument_types().size(), 1);

  llvm::SmallVector<RCReference<AsyncValue>, 1> results;
  results.resize(func->result_types().size());
  CHECK_EQ(results.size(), 1);