code: @Override
      public CreateSubscriberResult createSubscriber(CreateSubscriberRequest request) {
          request = beforeClientExecution(request);
          return executeCreateSubscriber(request);
      }
docs: <p>
  Creates a subscriber. You must create the associated budget and notification before you create the subscriber.
  </p>
  
  @param createSubscriberRequest
  Request of CreateSubscriber
  @return Result of the CreateSubscriber operation returned by the service.
  @throws InternalErrorException
  An error on the server occurred during the processing of your request. Try again later.
  @throws InvalidParameterException
  An error on the client occurred. Typically, the cause is an invalid input value.
  @throws CreationLimitExceededException
  You've exceeded the notification or subscriber limit.
  @throws DuplicateRecordException
  The budget name already exists. Budget names must be unique within an account.
  @throws NotFoundException
  We can’t locate the resource that you specified.
  @sample AWSBudgets.CreateSubscriber