@Override
    protected void transformQuery(Query query) {
        QueryRewrite.rewriteSddocname(query);
    }
Creates a Fastsearcher.

@param dispatcher the dispatcher used (when enabled) to send summary requests over the rpc protocol.
                  Eventually we will move everything to this protocol and never use dispatch nodes.
                  At that point we won't need a cluster searcher above this to select and pass the right
                  backend.
@param clusterParams the cluster number, and other cluster backend parameters
container-search/src/main/java/com/yahoo/prelude/fastsearch/IndexedBackend.java