ImmutableSortedMap.of("one", 1, "two", 2, "three", 3), "one", 1, "three", 3, "two", 2);
    assertMapEquals(
        ImmutableSortedMap.of("one", 1, "two", 2, "three", 3, "four", 4),
        "four",
        4,
        "one",
        1,
        "three",
        3,
        "two",
        2);
    assertMapEquals(
        ImmutableSortedMap.of("one", 1, "two", 2, "three", 3, "four", 4, "five", 5),
        "five",

  // 2048
  private static final long THREE_BYTE_SURROGATES = 2 * 1024;

  // 61,440 [chars 0x0800 to 0xFFFF, minus surrogates]
  private static final long THREE_BYTE_ROUNDTRIPPABLE_CHARACTERS =
      0xFFFF - 0x0800 + 1 - THREE_BYTE_SURROGATES;

  // 2,650,112
  private static final long EXPECTED_THREE_BYTE_ROUNDTRIPPABLE_COUNT =
      // All one byte characters

    assertMapEquals(
        ImmutableBiMap.of("one", 1, "two", 2, "three", 3), "one", 1, "two", 2, "three", 3);
    assertMapEquals(
        ImmutableBiMap.of("one", 1, "two", 2, "three", 3).inverse(),
        1,
        "one",
        2,
        "two",
        3,
        "three");
    assertMapEquals(
        ImmutableBiMap.of("one", 1, "two", 2, "three", 3, "four", 4),
        "one",
        1,
        "two",

    assertEquals("three", map.higherKey("one"));
    assertEquals("three", map.higherKey("r"));
    assertEquals("three", map.ceilingKey("r"));
    assertEquals("one", map.ceilingKey("one"));
    assertEquals(mapEntry("three", 5), map.higherEntry("one"));
    assertEquals(mapEntry("one", 3), map.ceilingEntry("one"));
    assertEquals("one", map.lowerKey("three"));

    registry.register(o1);

    Iterator<Subscriber> three = registry.getSubscribers("");
    assertEquals(s1, one.next().target);
    assertFalse(one.hasNext());

    assertEquals(s1, three.next().target);
    assertEquals(s2, three.next().target);
    assertEquals(o1, three.next().target);
    assertFalse(three.hasNext());

    three = registry.getSubscribers("");

    registry.unregister(s2);

    assertEquals("three", map.higherKey("one"));
    assertEquals("three", map.higherKey("r"));
    assertEquals("three", map.ceilingKey("r"));
    assertEquals("one", map.ceilingKey("one"));
    assertEquals(mapEntry("three", 5), map.higherEntry("one"));
    assertEquals(mapEntry("one", 3), map.ceilingEntry("one"));
    assertEquals("one", map.lowerKey("three"));

  }

  protected void populate(Multimap<String, Integer> multimap) {
    multimap.put("one", 1);
    multimap.put("two", 2);
    multimap.put("two", 22);
    multimap.put("three", 3);
    multimap.put("three", 33);
    multimap.put("three", 333);
  }

  @Override
  protected String getKeyNotInPopulatedMap() throws UnsupportedOperationException {
    return "zero";
  }

  @Override

        ImmutableMap.of("one", 1, "two", 2, "three", 3), "one", 1, "two", 2, "three", 3);
    assertMapEquals(
        ImmutableMap.of("one", 1, "two", 2, "three", 3, "four", 4),
        "one",
        1,
        "two",
        2,
        "three",
        3,
        "four",
        4);
    assertMapEquals(
        ImmutableMap.of("one", 1, "two", 2, "three", 3, "four", 4, "five", 5),
        "one",

  }

  protected void populate(Multimap<String, Integer> multimap) {
    multimap.put("one", 1);
    multimap.put("two", 2);
    multimap.put("two", 22);
    multimap.put("three", 3);
    multimap.put("three", 33);
    multimap.put("three", 333);
  }

  @Override
  protected String getKeyNotInPopulatedMap() throws UnsupportedOperationException {
    return "zero";
  }

  @Override

    registry.register(o1);

    Iterator<Subscriber> three = registry.getSubscribers("");
    assertEquals(s1, one.next().target);
    assertFalse(one.hasNext());

    assertEquals(s1, three.next().target);
    assertEquals(s2, three.next().target);
    assertEquals(o1, three.next().target);
    assertFalse(three.hasNext());

    three = registry.getSubscribers("");

    registry.unregister(s2);