@Test
public void testGetUserCharset_PropertyDoesNotExist() {

    // property does not exist => return null
    when(propertyManagerMock.findProperty(identityMock, null, null, null, UserServiceImpl.CHARSET)).thenReturn(null);
    String charsetValue = userServiceImpl.getUserCharset(identityMock);
    assertEquals("Wrong charset when no property exists, should return 'WebappHelper.getDefaultCharset()", charsetValue, WebappHelper.getDefaultCharset());
}