@Test
public void onScroll_withFourZigZags_shouldSetStateToFinished() throws Exception {

    performZigZag();
    assertThat(subject.getNumberOfZigzags()).isEqualTo(1);
    performZigZag();
    assertThat(subject.getNumberOfZigzags()).isEqualTo(2);
    performZigZag();
    assertThat(subject.getNumberOfZigzags()).isEqualTo(3);
    performZigZag();
    assertThat(subject.getNumberOfZigzags()).isEqualTo(4);
    assertZigZagState(FINISHED);
}