GuestOsService { public Long getGuestOsUuid(String guestOsName) { return this.guestOsJdbcDao.getGuestOsUuid(guestOsName); }  Long getGuestOsUuid(String guestOsName);  }
@Test public void getGuestOsUuidTest() { Mockito.doReturn(0l).when(guestOsJdbcDao).getGuestOsUuid(Mockito.anyString()); long result = spy.getGuestOsUuid("guestOsName"); Mockito.verify(guestOsJdbcDao).getGuestOsUuid(Mockito.anyString()); Assert.assertEquals(0l, result); }