public function getSlice( $offset, $length, $params = array() )
    {
        $searchResult = $this->handler->search( $this->form, $this->criteriaBuilder, $this->resultConverter, $offset, $length, $params );
        if ( !isset( $this->nbResults ) )
        {
            $this->nbResults = $searchResult->totalCount;
        }

        return $searchResult->searchHits;
    }