@Test
 public void testAlwaysReturnTheSameUserInstanceForTheSameUsername() {
   final String userName = "******";
   final User userFirstTime = inMemoryUserRepository.read(userName);
   final User userSecondTime = inMemoryUserRepository.read(userName);
   assertEquals(userFirstTime, userSecondTime);
 }
 /** Method: read(String userName) */
 @Test
 public void testGetAlwaysReturnsAUserEvenWhenEmpty() throws Exception {
   assertNotNull(inMemoryUserRepository.read("neverSeenUserName"));
 }