@Test
public void testGetNextUnusedViewHolder() throws Exception {

    //Given
    List<Shuffle.ViewHolder> viewHolderList = Arrays.asList(
        mockShuffleViewHolder(1),
        mockShuffleViewHolder(-1),
        mockShuffleViewHolder(2)
    );
    //When
    Shuffle.ViewHolder returnedHolder = Shuffle.getNextUnusedViewHolder(viewHolderList, 0);
    //Then
    assertThat(returnedHolder.position).isEqualTo(-1);
}