ChristmasTree { public List<ChristmasBranch> getBranches() { return branches; } ChristmasTree(int nbLine); @Override String toString(); List<ChristmasBranch> getBranches();  }
@Test public void shouldHaveThreeLinesForChristmasTree3() { ChristmasTree tree = new ChristmasTree(3); assertThat(tree.getBranches()).hasSize(3); }