@Test
public void getDefaultCoOwners_duplicateCoOwnerName() {

    String coOwnerName = "test3";
    Identity coOwnerIdentityMock = mock(Identity.class);
    String coOwnerConigValue = coOwnerName + "," + coOwnerName;
    when(campusConfigurationMock.getDefaultCoOwnerUserNames()).thenReturn(coOwnerConigValue);
    when(baseSecurityMock.findIdentityByName(coOwnerName)).thenReturn(coOwnerIdentityMock);
    // Exercise
    List<Identity> coOwners = campuskursCoOwnersTestObject.getDefaultCoOwners();
    assertEquals("Wrong number of owners, duplicate identity can be added only once", 1, coOwners.size());
}