static S deadlockedThreadsToString(L<ThreadInfo> threadInfo) {
  new L<S> out;
  int i = 0;
  Map<ThreadInfo, Thread> map = threadInfosToThreads_map(threadInfo);
  for (ThreadInfo threadInfo1 : threadInfo) {
    out.add("Thread " + (++i) + "/" + l(threadInfo) + ": ID=" + threadInfo1.getThreadId()
      + ", name=" + quote(threadInfo1.getThreadName()));
    out.add("  Trying to lock: " + threadInfo1.getLockName()
      + " which is owned by thread " + threadInfo1.getLockOwnerId()
      + " (" + quote(threadInfo1.getLockOwnerName()) + ")");
    // ThreadInfo.getStackTrace() doesn't work, so we look up the thread.
    Thread t = map.get(threadInfo1);
    if (t != null) {
      StackTraceElement[] st = t.getStackTrace();
      out.add("Stack trace (" + l(st) + "): ");
      out.add(indentx(stackTraceToString(st)));
    }
  }
  ret lines(out);
}