code: public ServiceFuture<UsageListResultInner> listAsync(String location, final ServiceCallback<UsageListResultInner> serviceCallback) {
          return ServiceFuture.fromResponse(listWithServiceResponseAsync(location), serviceCallback);
      }
docs: Get the usage for a subscription.
  
  @param location The identifier for the physical azure location.
  @param serviceCallback the async ServiceCallback to handle successful and failed responses.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the {@link ServiceFuture} object