Save `data` of downloaded `url` in `path`.

def _save(self, url, path, data):
        """Save `data` of downloaded `url` in `path`."""
        worker = self._workers[url]
        path = self._paths[url]

        if len(data):
            try:
                with open(path, 'wb') as f:
                    f.write(data)
            except Exception:
                logger.error((url, path))

        # Clean up
        worker.finished = True
        worker.sig_download_finished.emit(url, path)
        worker.sig_finished.emit(worker, path, None)
        self._get_requests.pop(url)
        self._workers.pop(url)
        self._paths.pop(url)