### Question:
App { public String getGreeting() { return "Hello world."; }  String getGreeting(); static void main(String[] args);  }### Answer:
@Test void appHasAGreeting() { App classUnderTest = new App(); assertNotNull(classUnderTest.getGreeting(), "app should have a greeting"); }
@Test public void testAppHasAGreeting() { App classUnderTest = new App(); assertNotNull("app should have a greeting", classUnderTest.getGreeting()); }