code: public List<String> getDocLintOpts() {
          String xdoclint = options.get(Option.XDOCLINT);
          String xdoclintCustom = options.get(Option.XDOCLINT_CUSTOM);
          if (xdoclint == null && xdoclintCustom == null)
              return List.nil();
  
          Set<String> doclintOpts = new LinkedHashSet<>();
          if (xdoclint != null)
              doclintOpts.add(DocLint.XMSGS_OPTION);
          if (xdoclintCustom != null) {
              for (String s: xdoclintCustom.split("\\s+")) {
                  if (s.isEmpty())
                      continue;
                  doclintOpts.add(DocLint.XMSGS_CUSTOM_PREFIX + s);
              }
          }
  
          if (doclintOpts.equals(Collections.singleton(DocLint.XMSGS_CUSTOM_PREFIX + "none")))
              return List.nil();
  
          String checkPackages = options.get(Option.XDOCLINT_PACKAGE);
          if (checkPackages != null) {
              for (String s : checkPackages.split("\\s+")) {
                  doclintOpts.add(DocLint.XCHECK_PACKAGE + s);
              }
          }
  
          String format = options.get(Option.DOCLINT_FORMAT);
          if (format != null) {
              doclintOpts.add(DocLint.XHTML_VERSION_PREFIX + format);
          }
  
          // standard doclet normally generates H1, H2,
          // so for now, allow user comments to assume that
          doclintOpts.add(DocLint.XIMPLICIT_HEADERS + "2");
          return List.from(doclintOpts.toArray(new String[doclintOpts.size()]));
      }
docs: Gets any options specifying how doclint should be run.
  An empty list is returned if no doclint options are specified
  or if the only doclint option is -Xdoclint:none.
  @return options for doclint