private void checkDepth(String s) {
      int oldDepth = depth;
      if (oldDepth != progressMap.size()) {
        depth = progressMap.size();
        throw new AssertionError("_Inconsistent depth " + s + "; depth=" + oldDepth + "; enters=" + enters + "; exits=" + exits + "; map=" + progressMap);
      }
    }
private void checkDepth(String s)