code: private SortedSet<String> findIdsPerName(final String indexName,
              final SortedMap<String, SortedSet<String>> names) {
          if (names.containsKey(indexName)) {
              return names.get(indexName);
          }
          final TreeSet<String> idsPerName = new TreeSet<String>();
          names.put(indexName, idsPerName);
          return idsPerName;
      }
docs: Find the set of IDs associated with a full name in the provided map.
  
  @param indexName the full name in index form
  @param names the map of full names to sets of IDs
  @return the set of ID strings