def url(self, pattern, method=None, name=None):
        """Decorator to map url pattern to the callable.

        Args:
            pattern (:obj:`str`): URL pattern to add. This is usually '/'
                separated path. Parts of the URL can be parameterised using
                curly braces.
                Examples: "/", "/path/to/resource", "/resoures/{param}"
            method (:obj:`str`, :obj:`list` of :obj:`str`, optional): HTTP
                methods for the path specied. By default, GET method is added.
                Value can be either a single method, by passing a string, or
                multiple methods, by passing a list of strings.
            name (:obj:`str`): Name for the pattern that can be used for
                reverse matching

        Note:
            A trailing '/' is always assumed in the pattern.

        Example:
            >>> @app.url(pattern='/path/to/resource', method='GET')
            >>> def function(ctx):
            >>>     return 'Hello world'

        See Also:
            :func:`drongo.managers.url.UrlManager.add`
        """
        def _inner(call):
            self._url_manager.add(pattern, method, call, name)
            return call
        return _inner