code: def get_certificate(self, certificate_uid):
          
          logging.debug('Retrieving certificate for uid=%s', certificate_uid)
  
          is_v1_uid = model.is_v1_uid(certificate_uid)
          if not is_v1_uid:
              return super(V1AwareCertificateStore, self).get_certificate(certificate_uid)
  
          # else it's V1.1 (if not valid, it will throw)
          certificate = self._find_certificate_metadata(uid=certificate_uid)
          if certificate:
              certificate_bytes = self._get_certificate_raw(certificate_uid)
              certificate_json = helpers.certificate_bytes_to_json(certificate_bytes)
              return model.to_certificate_model(certificate_json, certificate['txid'], certificate_bytes)
  
          message = 'Certificate metadata not found for certificate uid=%s' % certificate_uid
          logging.error(message)
          raise KeyError(message)
docs: Returns certificate as byte array. We need this for v1 certs, which compute a binary hash. Raises
          KeyError if not found
          :param certificate_uid:
          :return: