@Test
 public void testSetComputingStrategy() {
   StatementComputingStrategy computingStrategy = new StatementComputingStrategyRegular();
   movie.setComputingStrategy(computingStrategy);
   assertEquals(movie.getComputingStrategy(), computingStrategy);
 }
 @Test
 public void testComputingStrategy() {
   assertEquals(movie.getComputingStrategy(), computingStrategyChildren);
 }