code: String constructLogMsg() {
      final StringBuilder msg = new StringBuilder();
  
      for (final Map.Entry<String, List<StackTraceElement>> e : paramToStackTrace.build().entries()) {
        msg.append("Parameter ").append(e.getKey()).append(" accessed at \n");
        msg.append(FluentIterable.from(e.getValue())
            // but exclude code in Parameters itself
            .filter(not(IS_THIS_CLASS))
            .filter(not(IS_PARAMETERS_ITSELF))
            .filter(not(IS_THREAD_CLASS))
            .join(StringUtils.unixNewlineJoiner()));
        msg.append("\n\n");
      }
      return msg.toString();
    }
docs: pulled into method for testing