protected synchronized RequestFuture<Void> lookupCoordinator() {
        if (findCoordinatorFuture == null) {
            // find a node to ask about the coordinator
            Node node = this.client.leastLoadedNode();
            if (node == null) {
                log.debug("No broker available to send FindCoordinator request");
                return RequestFuture.noBrokersAvailable();
            } else {
                findCoordinatorFuture = sendFindCoordinatorRequest(node);
            }
        }
        return findCoordinatorFuture;
    }
Ensure that the coordinator is ready to receive requests. This will return
immediately without blocking. It is intended to be called in an asynchronous
context when wakeups are not expected.

@return true If coordinator discovery and initial connection succeeded, false otherwise
clients/src/main/java/org/apache/kafka/clients/consumer/internals/AbstractCoordinator.java