docs: def convert_values(args_list):
      """convert_value in bulk.
  
      :param args_list: list of value, source, target currency pairs
  
      :return: map of converted values
      """
      rate_map = get_rates(map(itemgetter(1, 2), args_list))
      value_map = {}
      for value, source, target in args_list:
          args = (value, source, target)
          if source == target:
              value_map[args] = value
          else:
              value_map[args] = value * rate_map[(source, target)]
  
      return value_map