More code for import routine.

app/Repositories/Bill/BillRepositoryInterface.php

@@ -98,6 +98,15 @@ interface BillRepositoryInterface
      */
     public function getBillsUnpaidInRange(Carbon $start, Carbon $end): string;
 
+    /**
+     * Get all bills with these ID's.
+     *
+     * @param array $billIds
+     *
+     * @return Collection
+     */
+    public function getByIds(array $billIds): Collection;
+
     /**
      * Get text or return empty string.
      *