code: def _ask_which_gist(self, matches):
          
          # ask user which gist to use
          self.hey("Use {} from which gist?".format(self.filename))
          for count, gist in enumerate(matches, 1):
              self.hey("[{}] {}".format(count, gist.get("description")))
  
          # get the gist index
          selected = False
          while not selected:
              gist_index = prompt("Type the number: ", type=int) - 1
              try:
                  selected = matches[gist_index]
              except IndexError:
                  self.oops("Invalid number, please try again.")
  
          self.output("Using `{}` Gist".format(selected["description"]))
          return selected
docs: Asks user which gist to use in case of more than one gist matching the
          instance filename.
          :param matches: (list) of dictioaries generated within select_gists()
          :return: (dict) of the selected gist