@Override
        public String toString() {
            return "LeaderState{"
                    + "allMembers=" + allMembers
                    + ", connectorOwners=" + connectorOwners
                    + ", taskOwners=" + taskOwners
                    + '}';
        }
Get the version of the connect protocol that is currently active in the group of workers.

@return the current connect protocol version
connect/runtime/src/main/java/org/apache/kafka/connect/runtime/distributed/WorkerCoordinator.java