anchor.diff:  {
     "book" : {
       "properties" : {
  -      "title" : { "type" : "string", "copy_to" : ["meta_data", "article_info"] },
  +      "title" : { "type" : "string", "copy_to" : ["meta_data", "article_info"] }
       }
   }
   --------------------------------------------------
  
positive.code:     "tweet" : {
          "properties" : {
              "hes_my_special_tweet" : {
                  "type" : "boolean",
              }
          }
      }
  
negative.code:     "tweet" : {
          "properties" : {
              "image" : {
                  "type" : "binary"
              }
          }
      }
  