def create_dss_message_attributes(package_id, submission_source, output_queue):
    """Create attributes for a DSpace Submission Service message."""
    dss_message_attributes = {
        "PackageID": {"DataType": "String", "StringValue": package_id},
        "SubmissionSource": {"DataType": "String", "StringValue": submission_source},
        "OutputQueue": {"DataType": "String", "StringValue": output_queue},
    }
    return dss_message_attributes