http_header = ['{}: {}'.format(key, val)
for (key, val) in list(self._headers.items())]
self._http_client.set_http_header(http_header)
http_header = ['{}: {}'.format(key, val)
for (key, val) in list(self._headers.items())]
self._http_client.set_http_header(http_header)