docs: def prompt_protocol():
      """
      Prompt user if they would like to save pickle file as a dictionary or an object.
  
      :return str: Answer
      """
      stop = 3
      ans = ""
      while True and stop > 0:
          ans = input("Save as (d)ictionary or (o)bject?\n"
                      "* Note:\n"
                      "Dictionaries are more basic, and are compatible with Python v2.7+.\n"
                      "Objects are more complex, and are only compatible with v3.4+ ")
          if ans not in ("d", "o"):
              print("Invalid response: Please choose 'd' or 'o'")
          else:
              break
      # if a valid answer isn't captured, default to dictionary (safer, broader)
      if ans == "":
          ans = "d"
      return ans