code: @Override
      public XBELHeader convert(Header source) {
          if (source == null) return null;
  
          XBELHeader xh = new XBELHeader();
  
          List<String> authors = source.getAuthors();
          if (hasItems(authors)) {
              XBELAuthorGroup xag = new XBELAuthorGroup();
              List<String> xauthors = xag.getAuthor();
              for (final String author : authors) {
                  xauthors.add(author);
              }
              xh.setAuthorGroup(xag);
          }
  
          List<String> licenses = source.getLicenses();
          if (hasItems(licenses)) {
              XBELLicenseGroup xlg = new XBELLicenseGroup();
              List<String> xlicenses = xlg.getLicense();
              for (final String license : licenses) {
                  xlicenses.add(license);
              }
              xh.setLicenseGroup(xlg);
          }
  
          String contactInfo = source.getContactInfo();
          String copyright = source.getCopyright();
          String description = source.getDescription();
          String disclaimer = source.getDisclaimer();
          String name = source.getName();
          String version = source.getVersion();
  
          xh.setContactInfo(contactInfo);
          xh.setCopyright(copyright);
          xh.setDescription(description);
          xh.setDisclaimer(disclaimer);
          xh.setName(name);
          xh.setVersion(version);
  
          return xh;
      }
docs: {@inheritDoc}