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Solve the following problem using Python, implementing the functions described below, one line at a time
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<USER_TASK:>
Description:
 def validate_header(header, header_auth, raw_header, data_key):
 """Validates the header using the header authentication data. :param header: Deserialized header :type header: aws_encryption_sdk.structures.MessageHeader :param header_auth: Deserialized header auth :type header_auth: aws_encryption_sdk.internal.structures.MessageHeaderAuthentication :type stream: io.BytesIO :param bytes raw_header: Raw header bytes :param bytes data_key: Data key with which to perform validation :raises SerializationError: if header authorization fails """

    _LOGGER.debug("Starting header validation")
    try:
        decrypt(
            algorithm=header.algorithm,
            key=data_key,
            encrypted_data=EncryptedData(header_auth.iv, b"", header_auth.tag),
            associated_data=raw_header,
        )
    except InvalidTag:
        raise SerializationError("Header authorization failed")