/**
* Create a metadata request for the given topics
*/
private ClientRequest metadataRequest(long now, int node, Set<String> topics) {
MetadataRequest metadata = new MetadataRequest(new ArrayList<String>(topics));
RequestSend send = new RequestSend(node, nextRequestHeader(ApiKeys.METADATA), metadata.toStruct());
return new ClientRequest(now, true, send, null);
}
/**
* Add a metadata request to the list of sends if we can make one