public SubClass isBounded() {
    this.isBoundedOptional = Optional.of(true);
    return (SubClass) this;
  }
If set, this stream will be considered a bounded stream. If all input streams in an application are
bounded, the job is considered to be running in batch processing mode.

@return this input descriptor
samza-api/src/main/java/org/apache/samza/system/descriptors/InputDescriptor.java