code: private Node parseParamTypeExpressionAnnotation(JsDocToken token) {
      checkArgument(token == JsDocToken.LEFT_CURLY);
  
      skipEOLs();
  
      Node typeNode = parseParamTypeExpression(next());
      if (typeNode != null) {
        if (!match(JsDocToken.RIGHT_CURLY)) {
          reportTypeSyntaxWarning("msg.jsdoc.missing.rc");
        } else {
          next();
        }
      }
  
      return typeNode;
    }
docs: ParamTypeExpressionAnnotation := '{' ParamTypeExpression '}'