start_time = :erlang.monotonic_time()
  

    Logger.info("Processed #{book.title} (#{book.author})")

    end_time = :erlang.monotonic_time()
    duration = :erlang.convert_time_unit(end_time - start_time, :native, :second)
    Logger.info("Processed \"#{book.title}\" (#{book.author}) for #{duration} seconds")