Method ToString

cpp/src/arrow/c/bridge_test.cc:1342–1342

  explicit MyDevice(int64_t value) : Device(true), value_(value) {}
  const char* type_name() const override { return kMyDeviceTypeName; }
  std::string ToString() const override { return kMyDeviceTypeName; }
  bool Equals(const Device& other) const override {
    if (other.type_name() != kMyDeviceTypeName || other.device_type() != device_type()) {
      return false;