anchor.diff:  
   [source,js]
   --------------------------------------------------
  -curl -XPOST 'http://localhost:9200/_field_stats?level=indices' -d '{
  +curl -XPOST "http://localhost:9200/_field_stats?level=indices" -d '{
      "fields" : ["rating"]
   }'
   --------------------------------------------------
  
positive.code: NOTE: Documents marked as deleted (but not yet removed by the merge process)
  still affect all the mentioned statistics.
  
  
  .Cluster level field statistics
  ==================================================
  
  [source,js]
  --------------------------------------------------
  GET /_field_stats?fields=rating,answer_count,creation_date,display_name
  --------------------------------------------------
  
  [source,json]
  --------------------------------------------------
  
negative.code: `gt`::  	Greater-than
  `lte`:: 	Less-than or equal to
  `lt`::  	Less-than
  