def GetSmallestThumbnail(media_thumbnail_list):
    """Helper function to get the smallest thumbnail of a list of
      gdata.media.Thumbnail.
    Returns gdata.media.Thumbnail """
    r = {}
    for thumb in media_thumbnail_list:
        r[int(thumb.width) * int(thumb.height)] = thumb
    keys = list(r.keys())
    keys.sort()
    return r[keys[0]]