// with `none` value,
    llvm::SmallVector<Value, 4> none_operands(
        input_max_num - op_input_num,
        builder.create<mlir::TFL::NoValueOp>(loc, builder.getNoneType(),
                                             builder.getUnitAttr()));
    op_state.addOperands(ArrayRef<Value>(none_operands));
  }

  if (op_name == "tfl.lstm") {