Protocol defaults?

Test.swift

protocol Search: UISearchResultsUpdating {
    func searchFor(query: String)
}

extension Search {
    func updateSearchResultsForSearchController(searchController: UISearchController) {
        searchFor(searchController.searchBar.text!)
    }
}

@objc class GoogleSearch: NSObject, Search {
    func searchFor(query: String) {
        // do stuff
    }
}

# Error: Type 'GoogleSearch' does not conform to protocol 'UISearchResultsUpdating'