@Test
public void testPureNext() {

    final ACompositeIterator<Integer> iter = new ACompositeIterator<> (Arrays.asList (
            Arrays.asList (1,2,3,4).iterator (),
            Arrays.asList (5,6,7,8).iterator (),
            Arrays.asList (9,10).iterator ()
    ));
    int expected = 1;
    while (expected <= 10) {
        int elem = iter.next ();
        assertEquals (expected, elem);
        expected++;
    }
    expectedException.expect (NoSuchElementException.class);
    iter.next ();
}