public function deleteSubscription($subscription, $optionalArgs = [])
{
$request = new DeleteSubscriptionRequest();
$request->setSubscription($subscription);
$mergedSettings = $this->defaultCallSettings['deleteSubscription']->merge(new CallSettings($optionalArgs));
$callable = ApiCallable::createApiCall($this->subscriberStub, 'DeleteSubscription', $mergedSettings, $this->descriptors['deleteSubscription']);
return $callable($request, [], ['call_credentials_callback' => $this->createCredentialsCallback()]);
}