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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 seal_aes_ctr_legacy(key_service, secret, digest_method=DEFAULT_DIGEST):
 """ Encrypts `secret` using the key service. You can decrypt with the companion method `open_aes_ctr_legacy`. """

    # generate a a 64 byte key.
    # Half will be for data encryption, the other half for HMAC
    key, encoded_key = key_service.generate_key_data(64)
    ciphertext, hmac = _seal_aes_ctr(
        secret, key, LEGACY_NONCE, digest_method,
    )
    return {
        'key': b64encode(encoded_key).decode('utf-8'),
        'contents': b64encode(ciphertext).decode('utf-8'),
        'hmac': codecs.encode(hmac, "hex_codec"),
        'digest': digest_method,
    }