### Question:
Emailer { public void sendGreetingEmailTo(User user) { RealEmailSender.sendEmailTo(user.email,"hello, "+ user.name); }  void sendGreetingEmailTo(User user); void sendByeByeEmailTo(User user);  }### Answer:
@Test public void shouldSendHelloEmail() throws Exception { new Emailer().sendGreetingEmailTo(aUser("email@gmail.com", "User")); }