code: private static void validateGeneration(int generation) {
      if (generation == CONTEXT_DEPTH_WARN_THRESH) {
        log.log(
            Level.SEVERE,
            "Context ancestry chain length is abnormally long. "
                + "This suggests an error in application code. "
                + "Length exceeded: " + CONTEXT_DEPTH_WARN_THRESH,
            new Exception());
      }
    }
docs: If the ancestry chain length is unreasonably long, then print an error to the log and record
  the stack trace.