anchor.diff:  
   `get`:: 		Get statistics, including missing stats.
   
  -`search`:: 		Search statistics, including custom grouping using the
  -				`groups` parameter (search operations can be associated with one or more
  -				groups).
  +`search`:: 		Search statistics. You can include statistics for custom groups by adding
  +                an extra `groups` parameter (search operations can be associated with one or more
  +                groups). The `groups` parameter accepts a comma separated list of group names.
  +                Use `_all` to return statistics for all groups.
   
   `warmer`:: 		Warmer statistics.
   `merge`:: 		Merge statistics.
  
positive.code: curl 'localhost:9200/_stats?clear=true&flush=true'
  # Get back stats for type1 and type2 documents for the my_index index
  curl 'localhost:9200/my_index/_stats?clear=true&indexing=true&types=type1,type2
  --------------------------------------------------
  
  The stats returned are aggregated on the index level, with
  
negative.code: curl localhost:9200/my_index/_stats/indexing
  # Indexing stats for my_index for my_type1 and my_type2
  curl localhost:9200/my_index/_stats/indexing/my_type1,my_type2
  # Search stats for group1 and group2
  curl 'localhost:9200/_stats/search/group1,group2
  --------------------------------------------------
  