anchor.diff:  }
   --------------------------------------------------
   
  +[[_order]]
   ==== Order
   
   By default the composite buckets are sorted by their natural ordering. Values are sorted
  
positive.code: \... will sort the composite bucket in descending order when comparing values from the `date_histogram` source
  and in ascending order when comparing values from the `terms` source.
  
  ==== Missing bucket
  
  By default documents without a value for a given source are ignored.
  
negative.code: }
  ----
  ////
  
  Although similar, the `terms` value source doesn't support the same set of
  parameters as the `terms` aggregation. For other supported value source
  parameters, see:
  
  * <<_order>>
  * <<_missing_bucket>>
  
  [[_histogram]]
  ===== Histogram
  