Adds handlers from a different Hug API to this one - to create a single API

def extend(self, api, route="", base_url="", http=True, cli=True, **kwargs):
        """Adds handlers from a different Hug API to this one - to create a single API"""
        api = API(api)

        if http and hasattr(api, '_http'):
            self.http.extend(api.http, route, base_url, **kwargs)

        if cli and hasattr(api, '_cli'):
            self.cli.extend(api.cli, **kwargs)

        for directive in getattr(api, '_directives', {}).values():
            self.add_directive(directive)

        for startup_handler in (api.startup_handlers or ()):
            self.add_startup_handler(startup_handler)