anchor.diff:  
   ==== Request Body
   
  -`source`:: The source index or index pattern.
  +`source`:: (object) The source configuration, consisting of `index` and optionally
  +a `query`.
   
  -`dest`:: The destination index.
  +`dest`:: (object) The destination configuration, consisting of `index`.
   
   `pivot`:: Defines the pivot function `group by` fields and the aggregation to
   reduce the data.
  
positive.code: --------------------------------------------------
  PUT _data_frame/transforms/ecommerce_transform
  {
    "source": "kibana_sample_data_ecommerce",
    "dest": "kibana_sample_data_ecommerce_transform",
    "pivot": {
      "group_by": {
        "customer_id": {
  
negative.code:   "acknowledged" : true
  }
  ----
  // NOTCONSOLE
  