@Override
    public UpdateGroupResult updateGroup(String groupId, UpdateGroupSpec groupSpec, UpdateGroupOptions options) {
        SimpleAdminApiFuture<CoordinatorKey, Void> future = UpdateGroupHandler.newFuture(groupId);
        UpdateGroupHandler handler = new UpdateGroupHandler(groupId, groupSpec, logContext);
        invokeDriver(handler, future, options.timeoutMs);
        return new UpdateGroupResult(future.get(CoordinatorKey.byGroupId(groupId)));
    }
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