assertEquals("", joiner.join(set));
    assertEquals("", joiner.join(set.iterator()));

    Object[] array = Lists.newArrayList(set).toArray(new Integer[0]);
    assertEquals("", joiner.join(array));

    StringBuilder sb1FromIterable = new StringBuilder();
    assertSame(sb1FromIterable, joiner.appendTo(sb1FromIterable, set));
    assertEquals(0, sb1FromIterable.length());

    assertNull(Optional.toJavaUtil(null));
    assertEquals(java.util.Optional.empty(), Optional.toJavaUtil(Optional.absent()));
    assertEquals(java.util.Optional.of("abc"), Optional.toJavaUtil(Optional.of("abc")));
  }

  public void testToJavaUtil_instance() {
    assertEquals(java.util.Optional.empty(), Optional.absent().toJavaUtil());
    assertEquals(java.util.Optional.of("abc"), Optional.of("abc").toJavaUtil());
  }

    assertEquals(State.NEW, service.state());
    assertFalse(service.isRunning());
    assertFalse(service.running);

    service.startAsync();
    assertEquals(State.RUNNING, service.state());
    assertTrue(service.isRunning());
    assertTrue(service.running);

    service.stopAsync();
    assertEquals(State.TERMINATED, service.state());
    assertFalse(service.isRunning());

          public void failed(State from, Throwable failure) {
            assertEquals(State.RUNNING, from);
            assertEquals(error, failure);
            latch.countDown();
          }
        },
        directExecutor());
    service.startAsync();
    latch.await();

    assertEquals(0, service.numberOfTimesRunCalled.get());
    assertEquals(Service.State.FAILED, service.state());
  }

    assertEquals(Collections.emptyList(), multimap.get("foo"));
    assertEquals(0, multimap.hashCode());
    assertTrue(multimap.isEmpty());
    assertEquals(HashMultiset.create(), multimap.keys());
    assertEquals(Collections.emptySet(), multimap.keySet());
    assertEquals(0, multimap.size());
    assertTrue(multimap.values().isEmpty());
    assertEquals("{}", multimap.toString());
  }

    assertEquals(Collections.emptySet(), multimap.get("foo"));
    assertEquals(0, multimap.hashCode());
    assertTrue(multimap.isEmpty());
    assertEquals(HashMultiset.create(), multimap.keys());
    assertEquals(Collections.emptySet(), multimap.keySet());
    assertEquals(0, multimap.size());
    assertTrue(multimap.values().isEmpty());
    assertEquals("{}", multimap.toString());
  }

        activityHelper.login(OptionalThing.empty());
        assertEquals("action:LOGIN\tuser:-\tpermissions:-", localLogMsg.get());

        activityHelper.login(createUser("testuser", new String[0]));
        assertEquals("action:LOGIN\tuser:testuser\tpermissions:-", localLogMsg.get());

        activityHelper.login(createUser("testuser", new String[] { "111", "222" }));

        assertEquals("", StringUtil.substringToLast("abc", "c"));
        assertEquals("c", StringUtil.substringToLast("abc", "b"));
        assertEquals("c", StringUtil.substringToLast("abcbc", "b"));
        assertEquals("abc", StringUtil.substringToLast("abc", ""));
        assertEquals("abc", StringUtil.substringToLast("abc", null));
        assertEquals("abc", StringUtil.substringToLast("abc", "dddd"));

    mac.init(MD5_KEY);
    mac.update(input.getBytes(UTF_8));
    assertEquals(knownOutput, HashCode.fromBytes(mac.doFinal()).toString());
    assertEquals(knownOutput, HashCode.fromBytes(mac.doFinal(input.getBytes(UTF_8))).toString());
    assertEquals(knownOutput, Hashing.hmacMd5(MD5_KEY).hashString(input, UTF_8).toString());
    assertEquals(knownOutput, Hashing.hmacMd5(MD5_KEY).hashBytes(input.getBytes(UTF_8)).toString());
  }

    assertEquals(0, matcher.countIn(s));
  }

  private void reallyTestAllMatches(CharMatcher matcher, CharSequence s) {
    assertTrue(matcher.matches(s.charAt(0)));
    assertEquals(0, matcher.indexIn(s));
    assertEquals(0, matcher.indexIn(s, 0));
    assertEquals(1, matcher.indexIn(s, 1));
    assertEquals(-1, matcher.indexIn(s, s.length()));
    assertEquals(s.length() - 1, matcher.lastIndexIn(s));