+ act_as_system_user do
+ required_uuids = Link.where("owner_uuid = ? and link_class = ? and name = ? and tail_uuid = ? and head_uuid like ?",
+ system_user_uuid,
+ 'signature',
+ 'require',
+ system_user_uuid,
+ Collection.uuid_like_pattern).
+ collect(&:head_uuid)
+
+ assert required_uuids.length > 0
+
+ signed_uuids = Link.where(owner_uuid: system_user_uuid,
+ link_class: 'signature',
+ name: 'click',
+ tail_uuid: users(:inactive).uuid,
+ head_uuid: required_uuids).
+ collect(&:head_uuid)
+
+ assert_equal 0, signed_uuids.length
+ end
+