anchor.diff:  
   [source,js]
   --------------------------------------------------
  +GET /_search
   {
       "_source": "obj.*",
       "query" : {
  
positive.code:     }
  }
  --------------------------------------------------
  
  The `_source` also accepts one or more wildcard patterns to control what parts of the `_source` should be returned:
  
  
negative.code: 
  [source,js]
  --------------------------------------------------
  GET /_search
  {
      "_source": false,
      "query" : {
  