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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 encrypt(content, salt=None, key=None, private_key=None, dh=None, auth_secret=None, keyid=None, keylabel="P-256", rs=4096, version="aes128gcm"):
 """ Encrypt a data block :param content: block of data to encrypt :type content: str :param salt: Encryption salt :type salt: str :param key: Encryption key data :type key: str :param private_key: DH private key :type key: object :param keyid: Internal key identifier for private key info :type keyid: str :param dh: Remote Diffie Hellman sequence :type dh: str :param rs: Record size :type rs: int :param auth_secret: Authorization secret :type auth_secret: str :param version: ECE Method version :type version: enumerate('aes128gcm', 'aesgcm', 'aesgcm128') :return: Encrypted message content :rtype str """

    def encrypt_record(key, nonce, counter, buf, last):
        encryptor = Cipher(
            algorithms.AES(key),
            modes.GCM(iv(nonce, counter)),
            backend=default_backend()
        ).encryptor()

        if version == 'aes128gcm':
            data = encryptor.update(buf + (b'\x02' if last else b'\x01'))
        else:
            data = encryptor.update((b"\x00" * versions[version]['pad']) + buf)
        data += encryptor.finalize()
        data += encryptor.tag
        return data

    def compose_aes128gcm(salt, content, rs, keyid):
        """Compose the header and content of an aes128gcm encrypted
        message body

        :param salt: The sender's salt value
        :type salt: str
        :param content: The encrypted body of the message
        :type content: str
        :param rs: Override for the content length
        :type rs: int
        :param keyid: The keyid to use for this message
        :type keyid: str

        """
        if len(keyid) > 255:
            raise ECEException("keyid is too long")
        header = salt
        if rs > MAX_RECORD_SIZE:
            raise ECEException("Too much content")
        header += struct.pack("!L", rs)
        header += struct.pack("!B", len(keyid))
        header += keyid
        return header + content

    if version not in versions:
        raise ECEException(u"Invalid version")

    if salt is None:
        salt = os.urandom(16)

    (key_, nonce_) = derive_key("encrypt", version=version,
                                salt=salt, key=key,
                                private_key=private_key, dh=dh,
                                auth_secret=auth_secret,
                                keyid=keyid, keylabel=keylabel)

    overhead = versions[version]['pad']
    if version == 'aes128gcm':
        overhead += 16
        end = len(content)
    else:
        end = len(content) + 1
    if rs <= overhead:
        raise ECEException(u"Record size too small")
    chunk_size = rs - overhead

    result = b""
    counter = 0

    # the extra one on the loop ensures that we produce a padding only
    # record if the data length is an exact multiple of the chunk size
    for i in list(range(0, end, chunk_size)):
        result += encrypt_record(key_, nonce_, counter,
                                 content[i:i + chunk_size],
                                 (i + chunk_size) >= end)
        counter += 1
    if version == "aes128gcm":
        if keyid is None and private_key is not None:
            kid = private_key.public_key().public_bytes(
                Encoding.X962,
                PublicFormat.UncompressedPoint)
        else:
            kid = (keyid or '').encode('utf-8')
        return compose_aes128gcm(salt, result, rs, keyid=kid)
    return result