private Map<Integer, Map<String, Long>> describeBrokerLevelThrottles(Admin admin, Collection<Integer> brokerIds) {
        return brokerIds.stream().collect(Collectors.toMap(Function.identity(), brokerId -> {
            ConfigResource brokerResource = new ConfigResource(ConfigResource.Type.BROKER, brokerId.toString());
            Config brokerConfigs = assertDoesNotThrow(() -> admin.describeConfigs(singleton(brokerResource)).values()
                    .get(brokerResource)
                    .get());
            return BROKER_LEVEL_THROTTLES.stream().collect(Collectors.toMap(Function.identity(),
                    name -> Optional.ofNullable(brokerConfigs.get(name)).map(e -> Long.parseLong(e.value())).orElse(-1L)));
        }));
    }
Describe the broker-level throttles in the cluster.

@return                A map whose keys are broker IDs and whose values are throttle
                       information.  The nested maps are keyed on throttle name.
tools/src/test/java/org/apache/kafka/tools/reassign/ReassignPartitionsCommandTest.java