code: function logNotice(book, key, message) {
      if (logged[key] || disabled[key]) return;
  
      logged[key] = true;
  
      var logger = book.getLogger();
      logger.warn.ln(message);
  }
docs: Log a deprecated notice
  
  @param {Book|Output} book
  @param {String} key
  @param {String} message