anchor.diff:  // TEST[continued]
   
   <1> This child document must be on the same shard than its grand-parent and parent
  -<2> The parent id of this document (must points to an `answer` document)+<2> The parent id of this document (must points to an `answer` document)
  
positive.code: 
  PUT my_index/_doc/2?refresh
  {
    "text": "This is a another question",
    "my_join_field": {
      "name": "question"
    }
  
negative.code:                                  |
                                  vote
  
  Indexing a grandchild document requires a `routing` value equals
  to the grand-parent (the greater parent of the lineage):
  
  
  