anchor.diff:  
   [source,console]
   --------------------------------------------------
  -PUT _ml/anomaly_detectors/test4
  +PUT _ml/anomaly_detectors/test3
   {
     "analysis_config":{
       "bucket_span": "10m",
  
positive.code: {anomaly-job}. For example, you can use the runtime fields in the analysis
  functions in one or more detectors. Runtime fields can impact search performance 
  based on the computation defined in the runtime script.
  
  * <<ml-configuring-transform1>>
  * <<ml-configuring-transform2>>
  
negative.code:   }
  }
  
  GET _ml/datafeeds/datafeed-test4/_preview
  --------------------------------------------------
  // TEST[skip:needs-licence]
  
  