pan><span style='background-color:#ccfecc'>(</span><span style='background-color:#d0ffd0'>out</span><span style='background-color:#ccfecc'>)</span>

if __name__ == &quot;__main__&quot;:
    key = &quot;Spam&quot;
    text = &quot;Hello, world!&quot;
    encoded = encode_decode(key, text)
    decoded = encode_decode(key, encoded)
    assert decoded == text
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