anchor.diff:  {
       "requests": [ ... ], <1>  
       "metric": { <2>
  -      "reciprocal_rank": { ... } <3>
  +      "mean_reciprocal_rank": { ... } <3>
      }
   }
   ------------------------------
  
positive.code:     }],
      "metric": {
         "dcg": {
              "normalize": false
         }
      }
  
negative.code: [cols="<,<",options="header",]
  |=======================================================================
  |Parameter |Description
  |`k` |sets the maximum number of documents retrieved per query. This value will act in place of the usual `size` parameter 
  in the query. Defaults to 10.
  |`normalize` | If set to `true`, this metric will calculate the https://en.wikipedia.org/wiki/Discounted_cumulative_gain#Normalized_DCG[Normalized DCG].
  |=======================================================================
  
  