anchor.diff:  
   To index a document with a join, the name of the relation and the optional parent
   of the document must be provided in the `source`.
  -For instance the following creates two parent documents in the `question` context:
  +For instance the following example creates two `parent` documents in the `question` context:
   
   [source,js]
   --------------------------------------------------
  
positive.code: // CONSOLE
  // TEST[continued]
  
  <1> This child document must be on the same shard than its parent
  <2> `answer` is the name of the join for this document
  <3> The parent id of this child document
  
  
negative.code: WARNING: It is required to index the lineage of a parent in the same shard so you must
  always route child documents using their greater parent id.
  
  For instance the following example shows how to index two `child` documents:
  
  [source,js]
  --------------------------------------------------
  