code: public ExtendedSwidProcessor setReleaseDate(final Date releaseDate) {
          swidTag.setReleaseDate(new DateTime(JAXBUtils.convertDateToXMLGregorianCalendar(releaseDate), idGenerator
                  .nextId()));
          return this;
      }
docs: Defines product release date (tag: release_date).
  
  @param releaseDate
  product release date
  @return a reference to this object.