/**
  * Find open messages.
  *
  * @param array $types
  *
  * @return mixed
  */
 protected function findNextMessages($types)
 {
     return $this->messageManager->findByTypes($types, MessageInterface::STATE_OPEN, $this->batchSize);
 }
 /**
  * Fill the inner buffer
  */
 protected function buffer()
 {
     $this->buffer = $this->messageManager->findByTypes($this->types, MessageInterface::STATE_OPEN, $this->batchSize);
 }