public function notify(Event $event)
 {
     if (!$event instanceof InvoiceIssued) {
         return;
     }
     $seller = $event->getSeller();
     $readModel = $this->loadReadModel();
     if (!isset($readModel[(string) $seller->getTaxIdNumber()])) {
         $readModel[(string) $seller->getTaxIdNumber()] = $this->initializeReadModelFor($seller);
     }
     $readModel[(string) $seller->getTaxIdNumber()]['issuedInvoices']++;
     file_put_contents($this->jsonReportPath, json_encode($readModel));
 }