anchor.diff:  [source,js]
   --------------------------------------------------
   {
  -    tag: {
  -        type:      "string",
  -        fielddata: {
  -            filter: {
  -                frequency: {
  -                    min:              0.001,
  -                    max:              0.1,
  -                    min_segment_size: 500
  +    "tag": {
  +        "type":      "string",
  +        "fielddata": {
  +            "filter": {
  +                "frequency": {
  +                    "min":              0.001,
  +                    "max":              0.1,
  +                    "min_segment_size": 500
                   }
               }
           }
  
positive.code: [source,js]
  --------------------------------------------------
  {
      tag: {
          type:      "string",
          fielddata: {
              format: "fst"
          }
      }
  }
  
negative.code: [source,js]
  --------------------------------------------------
  {
      "category": {
          "type":      "string",
          "fielddata": {
              "loading": "eager_global_ordinals"
          }
      }
  }
  