@Override
    public String toString() {
        return "ConsumerGroupMember(" +
            "memberId='" + memberId + '\'' +
            ", memberEpoch=" + memberEpoch +
            ", previousMemberEpoch=" + previousMemberEpoch +
            ", state='" + state + '\'' +
            ", instanceId='" + instanceId + '\'' +
            ", rackId='" + rackId + '\'' +
            ", rebalanceTimeoutMs=" + rebalanceTimeoutMs +
            ", clientId='" + clientId + '\'' +
            ", clientHost='" + clientHost + '\'' +
            ", subscribedTopicNames=" + subscribedTopicNames +
            ", subscribedTopicRegex='" + subscribedTopicRegex + '\'' +
            ", serverAssignorName='" + serverAssignorName + '\'' +
            ", assignedPartitions=" + assignedPartitions +
            ", partitionsPendingRevocation=" + partitionsPendingRevocation +
            ", classicMemberMetadata='" + classicMemberMetadata + '\'' +
            ')';
    }
@return A boolean indicating whether the member uses the classic protocol.
group-coordinator/src/main/java/org/apache/kafka/coordinator/group/modern/consumer/ConsumerGroupMember.java