def get_players_string(players):
  """
    Get players using formatted string: <username> (<agent>)...
  """
  if not players: # empty dict
    return "None"

  players_str = ""
  for user_id in players:
    player = players[user_id]
    username = player[0]
    agent = player[1]
    players_str += f"{username} ({agent}), "
  players_str = players_str[:-2]
  return players_str