Haiku { boolean isValidLineCount() { return haiku.matches("(.*)/(.*)/(.*)"); } Haiku(String haiku); List<Line> asLines();  }
@Test public void testThatGivenStringWith3Lines_returnsValidForLineCount() { String validFormatHaiku = "input/three/lines"; Haiku haiku = new Haiku(validFormatHaiku); assertThat(haiku.isValidLineCount()).isTrue(); }