@Test public void testNameOfTeens() { assertEquals("ten", ntn.nameOfTeens(10)); assertEquals("eleven", ntn.nameOfTeens(11)); assertEquals("twelve", ntn.nameOfTeens(12)); assertEquals("thirteen", ntn.nameOfTeens(13)); assertEquals("fourteen", ntn.nameOfTeens(14)); assertEquals("fifteen", ntn.nameOfTeens(15)); assertEquals("sixteen", ntn.nameOfTeens(16)); assertEquals("seventeen", ntn.nameOfTeens(17)); assertEquals("eighteen", ntn.nameOfTeens(18)); assertEquals("nineteen", ntn.nameOfTeens(19)); }