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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 libvlc_video_set_subtitle_file(p_mi, psz_subtitle):
    '''Set new video subtitle file.
    @param p_mi: the media player.
    @param psz_subtitle: new video subtitle file.
    @return: the success status (boolean).
    '''
    f = _Cfunctions.get('libvlc_video_set_subtitle_file', None) or \
        _Cfunction('libvlc_video_set_subtitle_file', ((1,), (1,),), None,
                    ctypes.c_int, MediaPlayer, ctypes.c_char_p)
    return f(p_mi, psz_subtitle)