anchor.diff:  
   `pre_filter` and `post_filter` can also be used to inject synonyms after
   candidates are generated. For instance for the query `captain usq` we
  -might generate a candidate `usa` for term `usq` which is a synonym for
  -`america` which allows to present `captain america` to the user if this
  +might generate a candidate `usa` for the term `usq`, which is a synonym for
  +`america`. This allows us to present `captain america` to the user if this
   phrase scores high enough.
  
positive.code:     variable, which should be used in your query.  You can still specify
      your own template `params` -- the `suggestion` value will be added to the
      variables you specify. Additionally, you can specify a `prune` to control
      if all phrase suggestions will be returned, when set to `true` the suggestions
      will have an additional option `collate_match`, which will be `true` if
      matching documents for the phrase was found, `false` otherwise.
      The default value for `prune` is `false`.
  
negative.code: `max_edits`::
      The maximum edit distance candidate suggestions can have
      in order to be considered as a suggestion. Can only be a value between 1
      and 2. Any other value results in a bad request error being thrown.
      Defaults to 2.
  
  `prefix_length`::
  