private function initManager(array $messages, $types, $batchSize)
 {
     $this->manager->expects($this->any())->method('findByTypes')->with($types, MessageInterface::STATE_OPEN, $batchSize)->willReturnCallback(function ($types, $state, $batchSize) use($messages) {
         return array_slice($messages, null, $batchSize);
     });
 }