import java.util.function.*; class Main { private static byte[] invoke(byte[] req) {return null;} private static String invoke(String req) {return null;} private static <T> void send(T req, Supplier<Function<T, T>> methodSelector) { System.out.println(req); System.out.println(methodSelector); } public static void main(final String[] args) throws Exception { send("", () -> Main::invoke); } }