// Try to read as specified subject
broker = brokerPool.get(subject);
collection = broker.openCollection(xmldbUri, Lock.READ_LOCK);
// Get all collections
Iterator<XmldbURI> collections = collection.collectionIteratorNoLock(broker); // QQ: use collectionIterator ?
while (collections.hasNext()) {
collectionURIs.add(xmldbUri.append(collections.next()));
}