@Test
public void readPhaseTapChanger() throws IOException {

    Network network = PhaseShifterTestCaseFactory.create();
    StringToIntMapper<AmplSubset> mapper = AmplUtil.createMapper(network);
    TwoWindingsTransformer twt = network.getTwoWindingsTransformer("PS1");
    PhaseTapChanger ptc = twt.getPhaseTapChanger();
    assertEquals(1, ptc.getTapPosition());
    ReadOnlyDataSource dataSource = new ResourceDataSource("ptc-test",
            new ResourceSet("/outputs/",
                    "ptc-test_ptc.txt"));
    AmplNetworkReader reader = new AmplNetworkReader(dataSource, network, mapper);
    reader.readPhaseTapChangers();
    assertEquals(2, ptc.getTapPosition());
}