FileDownloader::download

public function download(): Result
{
	$httpClient = new HttpClient();
	$tmpFile = $this->getTempPath();

	$result = new Result();
	do
	{
		if ($this->exponentialBackoffCounter > 0)
		{
			$rand = random_int(0, (int)$this->wait/2);
			usleep($rand + (2 ** $this->exponentialBackoffCounter) * $this->wait);
		}

		if (!$httpClient->download($this->downloadUrl, $tmpFile))
		{
			$this->exponentialBackoffCounter++;

			continue;
		}

		$status = $httpClient->getStatus();
		if ($status === 200)
		{
			$result->setData([
				'file' => $tmpFile,
			]);

			return $result;
		}

		if ($status > 501 && $status < 505)
		{
			$this->exponentialBackoffCounter++;

			continue;
		}

		$result->addError(new Error("Could not download file. Getting {$status}."));

		return $result;
	}
	while ($this->exponentialBackoffCounter <= self::MAX_BACKOFF_COUNTER);

	$result->addError(new Error("Could not download file."));

	return $result;
}