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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 make_permalink(img_id):
 """ Removes tmp prefix from filename and rename main and variant files. Returns img_id without tmp prefix. """

    profile, filename = img_id.split(':', 1)
    new_img_id = profile + ':' + remove_tmp_prefix_from_filename(filename)
    urls = get_files_by_img_id(img_id)
    if urls is None:
        return urls
    move_list = {(urls['main'], remove_tmp_prefix_from_file_path(urls['main']))}
    for var_label, var_file_path in urls['variants'].iteritems():
        move_list.add((var_file_path, remove_tmp_prefix_from_file_path(var_file_path)))
    for file_path_from, file_path_to in move_list:
        os.rename(media_path(file_path_from), media_path(file_path_to))
    return new_img_id