docs: def _BuildAuthenticatorResponse(self, app_id, client_data, plugin_response):
      """Builds the response to return to the caller."""
      encoded_client_data = self._Base64Encode(client_data)
      signature_data = str(plugin_response['signatureData'])
      key_handle = str(plugin_response['keyHandle'])
  
      response = {
          'clientData': encoded_client_data,
          'signatureData': signature_data,
          'applicationId': app_id,
          'keyHandle': key_handle,
      }
      return response