code: public static Matcher isPrivate() {
      return new Matcher() {
        @Override public boolean matches(Node node, NodeMetadata metadata) {
          JSDocInfo jsDoc = NodeUtil.getBestJSDocInfo(node);
          if (jsDoc != null) {
            return jsDoc.getVisibility() == Visibility.PRIVATE;
          }
          return false;
        }
      };
    }
docs: Returns a Matcher that matches against nodes that are declared {@code @private}.