@Test
@PrepareForTest({ ShipLauncher.class, System.class })

public void testExecute() {
  final ShipLauncher shipLauncher = spy(new ShipLauncher(DummyMessagePrinter.getInstance()));
  doNothing().when(shipLauncher).exit(anyInt());
  final Command command = mock(Command.class);
  shipLauncher.execute(command);
  verify(shipLauncher).exit(anyInt());
}