docs: public Object get(String key) {
          if (key != null && key.charAt(0) == '@') {
              String attributeName = key.substring(1);
              return attributes().get(attributeName);
          }
          if ("..".equals(key)) {
              return parent();
          }
          if ("*".equals(key)) {
              return children();
          }
          if ("**".equals(key)) {
              return depthFirst();
          }
          return getByName(key);
      }