The QuerySupport class has a method query that returns IndexResult. The IndexResult corresponds with the document, where the fields pass a condition defined as parameters of query method. Sometimes documents have more fields with the same name but only one match the condition. The issue is that all fields from the document are returned in the IndexResult and client has to filter the right field. 

Example: A document has field "controller" and a document contains:

Controller: First
Controller: Second
Controller: Third

When the query method is executed over the index and the parameters are: query type PREFIX and the prefix is "Sec", then the IndexResult contains as values all three controller fields from the document. I have to go trough the all values from the IndexResult and filter them to find the right controller. It means that I have to implement the same, what is in the QuerySupport already implemented.