anchor.diff:  // specific language governing permissions and limitations
   // under the License.
   
  -Document Transformers can be used to modify the information returned about each documents in the results of a query.
  +Document Transformers modify the information returned about documents in the results of a query.
   
   == Using Document Transformers
   
  
positive.code: 
  ==== Subquery Result Fields
  
  To appear in subquery document list, a field should be specified both fl parameters, in main one fl (despite the main result documents have no this field) and in subquery's one e.g., `foo.fl`. 
  Of course, you can use wildcard in any or both of these parameters. For example, if field `title` should appear in categories subquery, it can be done via one of these ways.
  
  [source,plain]
  ----
  
negative.code: * It must be given an unique name: `fl=*,children:[subquery]`
  * There might be a few of them, e.g., `fl=*,sons:[subquery],daughters:[subquery]`.
  * Every `[subquery]` occurrence adds a field into a result document with the given name, the value of this field is a document list, which is a result of executing subquery using document fields as an input.
  * Subquery will use the `/select` search handler by default, and will return an error if `/select` is not configured. This can be changed by supplying `foo.qt` parameter.
  
  Here is how it looks like using various formats:
  
  .XML
  [source,xml]
  ----
    <result name="response" numFound="2" start="0">
  