public void save(DataOutput out) throws IOException {
   final Set<Map.Entry<String, Long>> entries = myDependencies.entrySet();
   out.writeInt(entries.size());
   for (Map.Entry<String, Long> entry : entries) {
     IOUtil.writeString(entry.getKey(), out);
     out.writeLong(entry.getValue().longValue());
   }
 }