@Override
        public String toString() {
            return "Generation{" +
                    "generationId=" + generationId +
                    ", memberId='" + memberId + '\'' +
                    ", protocol='" + protocolName + '\'' +
                    '}';
        }
@return true if this generation has a valid member id, false otherwise. A member might have an id before
it becomes part of a group generation.
clients/src/main/java/org/apache/kafka/clients/consumer/internals/AbstractCoordinator.java