def METHOD_NAME(
    tastemaker_notifications_to_add, session
):
    specifier_group_ids_to_add = [
        (notification.specifier, notification.group_id)
        for notification in tastemaker_notifications_to_add
    ]
    existing_specifier_group_ids = (
        session.query(Notification.specifier, Notification.group_id)
        .filter(
            tuple_(Notification.specifier, Notification.group_id).in_(
                specifier_group_ids_to_add
            )
        )
        .all()
    )
    deduped_notifications = []
    for notification in tastemaker_notifications_to_add:
        if (
            notification.specifier,
            notification.group_id,
        ) not in existing_specifier_group_ids:
            deduped_notifications.append(notification)
    return deduped_notifications