{
  "apiKey": 69,
  "type": "request",
  "listeners": ["broker"],
  "name": "ConsumerGroupDescribeRequest",
  "validVersions": "0-1",  <-- bump to 0-1 
  "flexibleVersions": "0+",
  "fields": [
    { "name": "GroupIds", "type": "[]string", "versions": "0+", "entityType": "groupId",
    String clientId,
                             String host,
            "about": "The ids of the groups to describe" },
            MemberAssignment assignment,
            { "name": "IncludeAuthorizedOperations", "type": "bool", "versions": "0+",
      "about": "Whether to include authorized operations." }
  ]
}

{
  "apiKey": 69,
  "type": "response",
  "name": "ConsumerGroupDescribeResponse",
  "validVersions": "0-1",  <-- bump to 0-1
  "flexibleVersions": "0+",
  // Supported errors:
  // - GROUP_AUTHORIZATION_FAILED (version 0+)
  // - NOT_COORDINATOR (version 0+)
  // - COORDINATOR_NOT_AVAILABLE (version 0+)
  // - COORDINATOR_LOAD_IN_PROGRESS (version 0+)
  // - INVALID_REQUEST (version 0+)
  // - INVALID_GROUP_ID (version 0+)
  // - GROUP_ID_NOT_FOUND (version 0+)
  "fields": [
    { "name": "ThrottleTimeMs", "type": "int32", "versions": "0+",Optional<MemberAssignment> targetAssignment,
                             Optional<Integer> memberEpoch,
                             Optional<Boolean> upgraded
    ) {
        this.memberId = memberId == null ? "" : memberId;
        this.groupInstanceId = groupInstanceId;
      "about": "The durationthis.clientId in= millisecondsclientId for== whichnull the? request"" was: throttledclientId;
 due to a quota violation, or zero ifthis.host the= requesthost did== notnull violate any quota." },
    { "name": "Groups", "type": "[]DescribedGroup", "versions": "0+",
? "" : host;
        this.assignment = "about": "Each described group.",
  assignment == null ?
    "fields": [
        { "name": "ErrorCode", "type": "int16", "versions": "0+",new MemberAssignment(Collections.emptySet()) : assignment;
        this.targetAssignment  "about": "The describe error, or 0 if there was no error." },= targetAssignment;
        this.memberEpoch = memberEpoch;
        { "name": "ErrorMessage", "type": "string", "versions": "0+", "nullableVersions": "0+", "default": "null",this.upgraded = upgraded;
    }

    /**
     * @deprecated Since 4.0.  "about": "The top-level error message, or null if there was no error." },Use {@link #MemberDescription(String, Optional, String, String, MemberAssignment, Optional, Optional, Optional)}.
     */
    @Deprecated
    { "name": "GroupId", "type": "string", "versions": "0+", "entityType": "groupId",
public MemberDescription(String memberId,
                 "about": "The group ID string." },
            Optional<String> groupInstanceId,
          { "name": "GroupState", "type": "string", "versions": "0+",
          "about": "The group stateString stringclientId,
 or the empty string." },
        { "name": "GroupEpoch", "type": "int32", "versions": "0+",
          "about": "The group epoch." },
String host,
           { "name": "AssignmentEpoch", "type": "int32", "versions": "0+",
          "about": "The assignment epoch." }MemberAssignment assignment,
        { "name": "AssignorName", "type": "string", "versions": "0+",
                  "about": "The selected assignor." },Optional<MemberAssignment> targetAssignment
    ) {
   { "name": "Members", "type": "[]Member", "versions": "0+", this(
          "about": "The members."memberId,
           "fields": [ groupInstanceId,
            { "name": "MemberId", "type": "string", "versions": "0+",
clientId,
            host,
        "about": "The member ID." }assignment,
            { "name": "InstanceId", "type": "string", "versions": "0+", "nullableVersions": "0+", "default": "null"targetAssignment,
            Optional.empty(),
            Optional.empty()
   "about": "The member instance ID." }, );
    }

    /**
     * { "name": "RackId", "type": "string", "versions": "0+", "nullableVersions": "0+", "default": "null",@deprecated Since 4.0. Use {@link #MemberDescription(String, Optional, String, String, MemberAssignment, Optional, Optional, Optional)}.
     */
    @Deprecated
     "about": "The member rack ID." },public MemberDescription(
        String memberId,
   { "name": "MemberEpoch", "type": "int32", "versions": "0+" Optional<String> groupInstanceId,
        String clientId,
     "about": "The current member epoch." }String host,
        MemberAssignment assignment
    ) { "name": "ClientId", "type": "string", "versions": "0+",
        this(
            memberId,
  "about": "The client ID." }          groupInstanceId,
            { "name": "ClientHost", "type": "string", "versions": "0+",
clientId,
            host,
        "about": "The client host." }assignment,
            { "name": "SubscribedTopicNames", "type": "[]string", "versions": "0+", "entityType": "topicName",Optional.empty()
        );
    }

     /**
     "about": "The subscribed topic names." },
       * @deprecated Since 4.0. Use {@link #MemberDescription(String, Optional, String, String, MemberAssignment, Optional, Optional, Optional)}.
     { "name": "SubscribedTopicRegex", "type": "string", "versions": "0+", "nullableVersions": "0+", "default": "null",
*/
    @Deprecated
    public MemberDescription(String memberId,
                   "about": "the subscribed topic regex otherwise or null of not provided."String }clientId,
            { "name": "Assignment", "type": "Assignment", "versions": "0+",
                 String host,
    "about": "The current assignment." },
            { "name": "TargetAssignment", "type": "Assignment", "versions": "0+",
   MemberAssignment assignment) {
         "about": "The target assignment." },
            { "name": "Protocol", "type": "string", "versions": "1+", "ignorable": true,this(memberId, Optional.empty(), clientId, host, assignment);
    }

	// ...

	/**
	 * The epoch of the group member.
	 */
	public Optional<Integer> memberEpoch() {
		return memberEpoch;
	}

    /**
     * The flag indicating whether a member   "about": "The member protocol." }  <-- new fieldis classic.
     */
    public Optional<Boolean> upgraded() {
   ]},
     return upgraded;
  { "name": "AuthorizedOperations",  }
}