anchor.diff:  are distributed proportionally to each sub-request. Combine that with the point
   above about distribution being uneven and you should conclude that the using
   `size` with `slices` might not result in exactly `size` documents being
  -`_delete_by_query`ed.
  -* Each sub-requests gets a slightly different snapshot of the source index
  +deleted.
  +* Each sub-request gets a slightly different snapshot of the source index
   though these are all taken at approximately the same time.
   
   [float]
  
positive.code:  failures that are returned by the failing bulk request are returned in the `failures`
   element; therefore it's possible for there to be quite a few failed entities.
  
  If you'd like to count version conflicts rather than cause them to abort then
  set `conflicts=proceed` on the url or `"conflicts": "proceed"` in the request body.
  
  Back to the API format, this will delete tweets from the `twitter` index:
  
negative.code: ==== Automatic slicing
  
  You can also let delete-by-query automatically parallelize using
  <<sliced-scroll, sliced scroll>> to slice on `_id`. Use `slices` to specify the number of
  slices to use:
  
  [source,js]
  