+ # Give the special "System group" permission to manage this user and
+ # all of this user's stuff.
+ #
+ def add_system_group_permission_link
+ Link.create(link_class: 'permission',
+ name: 'can_manage',
+ tail_kind: 'arvados#group',
+ tail_uuid: system_group_uuid,
+ head_kind: 'arvados#user',
+ head_uuid: self.uuid)
+ end