'A helper method to register a rule (and optionally a view function)
to the application.  The endpoint is automatically prefixed with the
blueprint\'s name.'

def add_url_rule(self, rule, endpoint=None, view_func=None, **options):

    if self.url_prefix:
        rule = (self.url_prefix + rule)
    options.setdefault('subdomain', self.subdomain)
    if (endpoint is None):
        endpoint = _endpoint_from_view_func(view_func)
    defaults = self.url_defaults
    if ('defaults' in options):
        defaults = dict(defaults, **options.pop('defaults'))
    self.app.add_url_rule(rule, ('%s.%s' % (self.blueprint.name, endpoint)), view_func, defaults=defaults, **options)
