def _call(self, command, callback, extra_params=None):
    params = extra_params or {}
    params['Action'] = command
    now = datetime.utcnow().strftime('%a, %d %b %Y %H:%M:%S GMT')
    headers = {
      'Content-Type':'application/x-www-form-urlencoded',
      'Date':now,
      'X-Amzn-Authorization':'AWS3-HTTPS AWSAccessKeyId=%s, Algorithm=HMACSHA256, Signature=%s' %
                             (self._access_key, self._sign(now))
    }
    http = httpclient.AsyncHTTPClient()
    http.fetch(self.BASE_URL, functools.partial(self._on_request_completed, callback),
               headers=headers, method="POST",
               body=urllib.urlencode(params))
Writes a manifest entry to the manifest file for the url argument.
dataset/ETHPy150Open Cue/greplin-tornado-ses/src/greplin/tornado/ses.py/AmazonSes._call--crossover with--dataset/ETHPy150Open GoogleCloudPlatform/gsutil/gslib/copy_helper.py/Manifest._WriteRowToManifestFile