code: def get_rest_token(self):
          
          uri = urllib.parse.quote_plus(
              "https://{}.{}/{}".format(self.sb_name, self.namespace_suffix, self.eh_name))
          sas = self.sas_key.encode('utf-8')
          expiry = str(int(time.time() + 10000))
          string_to_sign = ('{}\n{}'.format(uri, expiry)).encode('utf-8')
          signed_hmac_sha256 = hmac.HMAC(sas, string_to_sign, hashlib.sha256)
          signature = urllib.parse.quote(base64.b64encode(signed_hmac_sha256.digest()))
          return 'SharedAccessSignature sr={}&sig={}&se={}&skn={}' \
                  .format(uri, signature, expiry, self.policy)
docs: Returns an auth token for making calls to eventhub REST API.
  
          :rtype: str