Method AppendString

cpp/src/arrow/array/array_union_test.cc:509–513

  }

  void AppendString(const std::string& str) override {
    Base::AppendString(str);
    ASSERT_OK(i8_builder->AppendEmptyValue());
    ASSERT_OK(dbl_builder->AppendEmptyValue());
  }

  void AppendDouble(double dbl) override {
    Base::AppendDouble(dbl);