@Test
public void testNeighbouringHashes() {

    String center = "dqcjqc";
    Set<String> neighbours = Sets.newHashSet("dqcjqf", "dqcjqb", "dqcjr1",
            "dqcjq9", "dqcjqd", "dqcjr4", "dqcjr0", "dqcjq8");
    assertEquals(neighbours, Sets.newHashSet(neighbours(center)));
}