public Map<String, PartitionsSpec> materialize() {
        HashMap<String, PartitionsSpec> all = new HashMap<>();
        for (Map.Entry<String, PartitionsSpec> entry : map.entrySet()) {
            String topicName = entry.getKey();
            PartitionsSpec partitions = entry.getValue();
            for (String expandedTopicName : StringExpander.expand(topicName))
                all.put(expandedTopicName, partitions);
        }
        return all;
    }
Enumerate the partitions inside this TopicsSpec.

@return      A map from topic names to PartitionsSpec objects.
trogdor/src/main/java/org/apache/kafka/trogdor/workload/TopicsSpec.java