Arvados

When in Arvagrant I run the following command multiple times

arv link create \
  --link '{ "tail_uuid":"y5x3o-j7d0g-fffffffffffffff",
            "head_uuid":"y5x3o-s0uqq-1t1gwxlgz82qe88",
            "link_class":"permission",
            "name":"can_read" 
          }'

they all succeed. After that, N items with the same relevant data can be obtained when querying the Arvados API host

[root@shell ~]# arv link list --filters '[["tail_uuid" , "=", "y5x3o-j7d0g-fffffffffffffff"], ["head_uuid", "=", "y5x3o-s0uqq-1t1gwxlgz82qe88"], ["link_class", "=", "permission"], ["name",  "=", "can_read"]]'
{
 "kind":"arvados#linkList",
 "etag":"",
 "self_link":"",
 "offset":0,
 "limit":100,
 "items":[
  {
   "href":"/links/y5x3o-o0j2j-gbuzeh9wadkfdk1",
   "kind":"arvados#link",
   "etag":"dqvyhhstb49krfitqpom3ryr3",
   "uuid":"y5x3o-o0j2j-gbuzeh9wadkfdk1",
   "owner_uuid":"y5x3o-tpzed-000000000000000",
   "created_at":"2016-11-14T16:18:48.274021000Z",
   "modified_by_client_uuid":"y5x3o-ozdt8-va8xlz0w1l7z1md",
   "modified_by_user_uuid":"y5x3o-tpzed-000000000000000",
   "modified_at":"2016-11-14T16:18:48.273529000Z",
   "tail_uuid":"y5x3o-j7d0g-fffffffffffffff",
   "link_class":"permission",
   "name":"can_read",
   "head_uuid":"y5x3o-s0uqq-1t1gwxlgz82qe88",
   "head_kind":"arvados#repository",
   "tail_kind":"arvados#group",
   "properties":{}
  },
  {
   "href":"/links/y5x3o-o0j2j-3frdd7vi82w7bf7",
   "kind":"arvados#link",
   "etag":"42hpechxyyx6mmbmvgu09edmr",
   "uuid":"y5x3o-o0j2j-3frdd7vi82w7bf7",
   "owner_uuid":"y5x3o-tpzed-000000000000000",
   "created_at":"2016-11-11T19:33:05.533451000Z",
   "modified_by_client_uuid":"y5x3o-ozdt8-va8xlz0w1l7z1md",
   "modified_by_user_uuid":"y5x3o-tpzed-000000000000000",
   "modified_at":"2016-11-11T19:33:05.532937000Z",
   "tail_uuid":"y5x3o-j7d0g-fffffffffffffff",
   "link_class":"permission",
   "name":"can_read",
   "head_uuid":"y5x3o-s0uqq-1t1gwxlgz82qe88",
   "head_kind":"arvados#repository",
   "tail_kind":"arvados#group",
   "properties":{}
  }
 ],
 "items_available":2
}

If you compare the items, "owner_uuid / tail_uuid / link_class / name / head_uuid / head_kind / tail_kind / properties" are identical and therefore they're the same?