docs: public Node addAnchor(String a, Node n) {
  //         System.err.println("addAnchor(" + a + ", " + n + ")");
  
          n.anchor = a;
          if(bad_anchors != null) {
  //             System.err.print(" -- bad_anchors != null\n");
              if(bad_anchors.containsKey(a)) {
  //                 System.err.print(" -- st_lookup(p->bad_anchors) succeeded\n");
                  if(n.kind != KindTag.Str) {
                      Node bad = bad_anchors.get(a);
  //                     System.err.print(" -- this is not a str\n");
  //                     System.err.print(" -- id: " + n.id + ", bad.id: " + bad.id +"\n");
                      n.id = bad.id;
                      handler.handle(this, n);
                  }
              }
          }
          if(anchors == null) {
  //             System.err.print(" -- anchors == null\n");
              anchors = new HashMap<String, Node>();
          }
  //         System.err.print(" -- inserting into the anchor again\n");
          anchors.put(a, n);
          return n;
      }