Method version

codelab/network_functions.h:82–82

  NetworkAddressRep& operator=(NetworkAddressRep&& other) = default;

  IpVersion version() const { return version_; }

  bool IsZeroValue() const { return version_ == IpVersion::kUnset; }
  bool IsIPv4() const { return version_ == IpVersion::kIPv4; }