code: @Exported
      public Set<Node> getNodes() {
          Set<Node> nodes = this.nodes;
          if(nodes!=null) return nodes;
  
          Set<Node> r = new HashSet<>();
          Jenkins h = Jenkins.getInstance();
          if(this.matches(h))
              r.add(h);
          for (Node n : h.getNodes()) {
              if(this.matches(n))
                  r.add(n);
          }
          return this.nodes = Collections.unmodifiableSet(r);
      }
docs: Gets all {@link Node}s that belong to this label.