public static ConsumerGroupHeartbeatRequest parse(ByteBuffer buffer, short version) {
        return new ConsumerGroupHeartbeatRequest(new ConsumerGroupHeartbeatRequestData(
            new ByteBufferAccessor(buffer), version), version);
    }
A member epoch of <code>0</code> means that the member wants to join the group.
clients/src/main/java/org/apache/kafka/common/requests/ConsumerGroupHeartbeatRequest.java