def update(notification_id, label, plugin_name, options, description, active, added_certificates, removed_certificates):
    """
    Updates an existing notification.

    :param notification_id:
    :param label: Notification label
    :param plugin_name:
    :param options:
    :param description:
    :param active:
    :param added_certificates:
    :param removed_certificates:
    :rtype: Notification
    :return:
    """
    notification = get(notification_id)

    notification.label = label
    notification.plugin_name = plugin_name
    notification.options = options
    notification.description = description
    notification.active = active
    notification.certificates = notification.certificates + added_certificates
    notification.certificates = [c for c in notification.certificates if c not in removed_certificates]

    return database.update(notification)

    Updates an existing notification.

    :param notification_id:
    :param label: Notification label
    :param plugin_name:
    :param options:
    :param description:
    :param active:
    :param added_certificates:
    :param removed_certificates:
    :rtype: Notification
    :return:
    
lemur/notifications/service.py