String (final PersistentHashMap<String, String> map) { map.force(); final PHMEntry entry = mapsEntries.get(map); assert entry != null : "No entry for " + map + ": only maps created by .createPHMap() are allowed"; final StringBuilder sb = new StringBuilder(); for (File file : entry.directory.listFiles()) { sb.append(file.getName()) .append(": ") .append(sha256Hex(file.toPath())) .append('\n'); } return sb.toString(); }