def METHOD_NAME(file):
    warn = 'Not a OpenType font' if path.splitext(file)[1] != '.ttc' \
        else 'a Font Collection that has Not a OpenType font'
    input_path = get_input_path(file)
    out_path = path.join(get_temp_dir_path(), file)
    assert path.exists(out_path) is False
    msg_path = runner(CMD + ['-s', '-e', '-o', 'o', f'_{out_path}',
                             '=post-format', '_2', '-f', input_path])
    assert path.exists(out_path) is False
    with open(msg_path, 'rb') as f:
        output = f.read()
    assert (f'WARNING: "{input_path}" cannot be converted '
            f'since it is {warn}').encode() in output