anchor.diff:                  "_score": null,
                   "_routing": "1",
                   "_source": {
  -                    "text": "This is a child document",
  +                    "text": "This is an answer",
                       "my_join_field": {
  -                        "name": "my_child", <3>
  +                        "name": "answer", <3>
                           "parent": "1"  <4>
                       }
                   },
  
positive.code: // TEST[continued]
  
  <1> This child document must be on the same shard than its grandparent and parent
  <2> The parent id of this document (must points to an `another_child` document)
  
  
  
negative.code:         "my_join_field": {
            "type": "join",
            "relations": {
              "question": ["answer", "comment"]  <1>
            }
          }
        }
  