IPv4GroupInterface
typedef IPv4GroupInterface ValueType;
IPv4GroupInterface* state = groupIterator.Next();
state->Mode() == IPv4GroupInterface::kExclude
IPv4GroupInterface::AddressSet::Iterator addressIterator
IPv4GroupInterface* state = it.Next();
IPv4Multicast::JoinGroup(IPv4GroupInterface* state)
IPv4Multicast::LeaveGroup(IPv4GroupInterface* state)
ipv4_delta_group(IPv4GroupInterface* group, int option,
IPv4GroupInterface* state = NULL;