feat: allow retrieving the query object

src/BookSearch/BookSearch.php

@@ -104,6 +104,10 @@ class BookSearch
         $this->filterQueryParts[] = sprintf('%s:[%s TO %s]', $field, $min, $max);
     }
 
+    public function getQuery() {
+        return $this->query;
+    }
+
     public function addSortField($field, $order = \SolrQuery::ORDER_DESC)
     {
         $this->query->addSortField($field, $order);