@Override
    public boolean hasReadyNodes(long now) {
        return connections.values().stream().anyMatch(cxn -> cxn.isReady(now));
    }
Raise an unsupported version error on the next request if it matches the given matcher.
If the matcher does not match, {@link KafkaClient#send(ClientRequest, long)} will throw IllegalStateException.
@param matcher The request matcher to apply
clients/src/test/java/org/apache/kafka/clients/MockClient.java