private void throwIfClassicProtocolIsNotSupported(
        ConsumerGroup group,
        String memberId,
        String protocolType,
        JoinGroupRequestProtocolCollection protocols
    ) {
        if (!group.supportsClassicProtocols(protocolType, ClassicGroupMember.plainProtocolSet(protocols))) {
            throw Errors.INCONSISTENT_GROUP_PROTOCOL.exception("Member " + memberId + "'s protocols are not supported.");
        }
    }
Validates if the received classic member protocols are supported by the group.

@param group         The ConsumerGroup.
@param memberId      The joining member id.
@param protocolType  The joining member protocol type.
@param protocols     The joining member protocol collection.
group-coordinator/src/main/java/org/apache/kafka/coordinator/group/GroupMetadataManager.java