@Test
 public void addCoinsForUserTestCase002() throws Exception {
   // coins = null
   coinsTxnService.addCoinsForUser(11L, null);
   int coins = coinsTxnService.getCoinsByUserId(11L);
   Assert.assertEquals(10, coins);
 }
 @Test
 public void getCoinsByUserIdTestCase001() throws Exception {
   // 此用户不存在
   coinsTxnService.addCoinsForUser(10L, 10);
   Integer coins = coinsTxnService.getCoinsByUserId(15L);
   Assert.assertEquals(null, coins);
 }
 @Test
 public void addCoinsForUserTestCase001() throws Exception {
   // 正常case
   coinsTxnService.addCoinsForUser(1000L, 10);
   int coins = coinsTxnService.getCoinsByUserId(1000L);
   Assert.assertEquals(10, coins);
 }
 @Test
 public void transferTestCase003() throws Exception {
   // 转出或者转入用户金额不存在
   coinsTxnService.transfer(1000L, 11L, Integer.valueOf(5));
   Integer coin1 = coinsTxnService.getCoinsByUserId(1000L);
   Integer coin2 = coinsTxnService.getCoinsByUserId(10L);
   Assert.assertEquals(5, coin1.intValue());
   Assert.assertEquals(15, coin2.intValue());
 }
 @Test
 public void getCoinsByUserIdTestCase002() throws Exception {
   // 正常得到100
   Integer coins = coinsTxnService.getCoinsByUserId(1000L);
   Assert.assertEquals(10, coins.intValue());
 }