anchor.diff:  }
   --------------------------------------------------
   
  -The above will sort the countries buckets based on the average height among the female population.
  +The above will sort the artist's countries buckets based on the average play count among the rock songs.
   
   Multiple criteria can be used to order the buckets by providing an array of order criteria such as the following:
   
  
positive.code: --------------------------------------------------
  {
      "aggs" : {
          "genders" : {
              "terms" : {
                  "field" : "gender",
                  "order" : { "avg_height" : "desc" }
              },
              "aggs" : {
                  "avg_height" : { "avg" : { "field" : "height" } }
              }
          }
      }
  
negative.code:     "aggs" : {
          "countries" : {
              "terms" : {
                  "field" : "artist.country",
                  "order" : { "rock>playback_stats.avg" : "desc" }
              },
              "aggs" : {
                  "rock" : {
                      "filter" : { "term" : { "genre" :  "rock" }},
                      "aggs" : {
                          "playback_stats" : { "stats" : { "field" : "play_count" }}
                      }
                  }
              }
  