@Test
public void nextMAt0() {

    AbstractVFState state = create(5, 10);
    assertThat(state.nextM(0, -1), is(0));
    assertThat(state.nextM(0, 0), is(1));
    assertThat(state.nextM(0, 1), is(2));
    assertThat(state.nextM(0, 2), is(3));
}