code: def create_random_context(dialog, rng, minimum_context_length=2, max_context_length=20):
      
      # sample dialog context
      #context_turns = rng.randint(minimum_context_length,len(dialog)-1)
      max_len = min(max_context_length, len(dialog)) - 2
      if max_len <= minimum_context_length:
          context_turns = max_len
      else:
          context_turns = rng.randint(minimum_context_length, max_len)
  
      # create string
      return dialog_turns_to_string(dialog[:context_turns]), context_turns
docs: Samples random context from a dialog. Contexts are uniformly sampled from the whole dialog.
      :param dialog:
      :param rng:
      :return: context, index of next utterance that follows the context