anchor.diff:  --------------------------------------------------
   // NOTCONSOLE
   
  -==== Other Parameters
  +[[scripted-metric-aggregation-parameters]]
  +==== Other parameters
   
   [horizontal]
   params::           Optional. An object whose contents will be passed as variables to the  `init_script`, `map_script` and `combine_script`. This can be
  
positive.code: --------------------------------------------------
  // NOTCONSOLE
  
  ==== Empty Buckets
  
  If a parent bucket of the scripted metric aggregation does not collect any documents an empty aggregation response will be returned from the
  shard with a `null` value. In this case the `reduce_script`'s `states` variable will contain `null` as a response from that shard.
  
negative.code: 
  For more details on specifying scripts see <<modules-scripting, script documentation>>.
  
  [[scripted-metric-aggregation-return-types]]
  ==== Allowed return types
  
  Whilst any valid script object can be used within a single script, the scripts must return or store in the `state` object only the following types:
  