prefetchExistences example

$deletes[] = $this->factory->resolveDelete($definition, $operation->getPayload());

                $notFound[] = $this->extractDeleteCommands($definition, $operation->getPayload(), $context, $commandQueue);

                continue;
            }

            if ($operation->getAction() === SyncOperation::ACTION_UPSERT) {
                $parameters = new WriteParameterBag($definition, $context, '', $commandQueue);

                $payload = $this->commandExtractor->normalize($definition, $operation->getPayload(), $parameters);
                $this->gateway->prefetchExistences($parameters);

                $key = $operation->getKey();

                foreach ($payload as $index => $row) {
                    $parameters->setPath('/' . $key . '/' . $index);
                    $context->resetPaths();
                    $this->commandExtractor->extract($row, $parameters);
                }

                $writes[] = $this->factory->resolveWrite($definition, $payload);
            }
        }