code: public ServiceFuture<SubscriptionInner> getAsync(String subscriptionId, final ServiceCallback<SubscriptionInner> serviceCallback) {
          return ServiceFuture.fromResponse(getWithServiceResponseAsync(subscriptionId), serviceCallback);
      }
docs: Gets details about a specified subscription.
  
  @param subscriptionId The ID of the target subscription.
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object