docs: public static Set<LabelAtom> parse(String labels) {
          final Set<LabelAtom> r = new TreeSet<>();
          labels = fixNull(labels);
          if(labels.length()>0) {
              final QuotedStringTokenizer tokenizer = new QuotedStringTokenizer(labels);
              while (tokenizer.hasMoreTokens())
                  r.add(Jenkins.getInstance().getLabelAtom(tokenizer.nextToken()));
              }
          return r;
      }