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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def probePlayer(requested_player=''):
 """ Probes the multimedia players which are available on the host system."""

    ret_player = None
    if logger.isEnabledFor(logging.INFO):
        logger.info("Probing available multimedia players...")
    implementedPlayers = Player.__subclasses__()
    if logger.isEnabledFor(logging.INFO):
        logger.info("Implemented players: " +
                    ", ".join([player.PLAYER_CMD
                              for player in implementedPlayers]))

    if requested_player:
        req = requested_player.split(',')
        for r_player in req:
            if r_player == 'vlc':
                r_player = 'cvlc'
            for player in implementedPlayers:
                if player.PLAYER_CMD == r_player:
                    ret_player = check_player(player)
                    if ret_player is not None:
                        return ret_player
            if ret_player is None:
                if logger.isEnabledFor(logging.INFO):
                    logger.info('Requested player "{}" not supported'.format(r_player))
    else:
        for player in implementedPlayers:
            ret_player = check_player(player)
            if ret_player is not None:
                break
    return ret_player