private <K, V> void maybeSendRequests(AdminApiDriver<K, V> driver, long currentTimeMs) {
        for (AdminApiDriver.RequestSpec<K> spec : driver.poll()) {
            runnable.call(newCall(driver, spec), currentTimeMs);
        }
    }
Returns the broker id pertaining to the given resource, or null if the resource is not associated
with a particular broker.
clients/src/main/java/org/apache/kafka/clients/admin/KafkaAdminClient.java