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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 source_data_key_length_check(source_data_key, algorithm):
 """Validates that the supplied source_data_key's data_key is the correct length for the supplied algorithm's kdf_input_len value. :param source_data_key: Source data key object received from MasterKey decrypt or generate data_key methods :type source_data_key: :class:`aws_encryption_sdk.structures.RawDataKey` or :class:`aws_encryption_sdk.structures.DataKey` :param algorithm: Algorithm object which directs how this data key will be used :type algorithm: aws_encryption_sdk.identifiers.Algorithm :raises InvalidDataKeyError: if data key length does not match required kdf input length """

    if len(source_data_key.data_key) != algorithm.kdf_input_len:
        raise InvalidDataKeyError(
            "Invalid Source Data Key length {actual} for algorithm required: {required}".format(
                actual=len(source_data_key.data_key), required=algorithm.kdf_input_len
            )
        )