public void testCommonPrefix() {
    assertEquals("", Strings.commonPrefix("", ""));
    assertEquals("", Strings.commonPrefix("abc", ""));
    assertEquals("", Strings.commonPrefix("", "abc"));
    assertEquals("", Strings.commonPrefix("abcde", "xyz"));
    assertEquals("", Strings.commonPrefix("xyz", "abcde"));
    assertEquals("", Strings.commonPrefix("xyz", "abcxyz"));
    assertEquals("a", Strings.commonPrefix("abc", "aaaaa"));

  public void testLower() {
    resetWithHole();
    assertEquals(null, navigableMap.lowerEntry(a.getKey()));
    assertEquals(null, navigableMap.lowerKey(a.getKey()));
    assertEquals(a, navigableMap.lowerEntry(b.getKey()));
    assertEquals(a.getKey(), navigableMap.lowerKey(b.getKey()));
    assertEquals(a, navigableMap.lowerEntry(c.getKey()));
    assertEquals(a.getKey(), navigableMap.lowerKey(c.getKey()));
  }

    assertEquals(0, counter.getCount());
    assertEquals(0, counter.read());
    assertEquals(1, counter.getCount());
  }

  public void testReadArray() throws IOException {
    assertEquals(10, counter.read(new byte[10]));
    assertEquals(10, counter.getCount());
  }

  public void testReadArrayRange() throws IOException {
    assertEquals(3, counter.read(new byte[10], 1, 3));

    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));

    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));

    assertEquals(0, actual.indexOf(list(1, 3)));
    assertEquals(1, actual.indexOf(list(1, 4)));
    assertEquals(2, actual.indexOf(list(2, 3)));
    assertEquals(3, actual.indexOf(list(2, 4)));
    assertEquals(-1, actual.indexOf(list(3, 1)));

    assertEquals(-1, actual.indexOf(list(1)));
    assertEquals(-1, actual.indexOf(list(1, 1, 1)));
  }

    // also test available
    lin.mark(2);
    assertEquals(2, lin.available());
    int read = lin.read();
    assertEquals(big[0], read);
    assertEquals(1, lin.available());
    read = lin.read();
    assertEquals(big[1], read);
    assertEquals(0, lin.available());
    read = lin.read();
    assertEquals(-1, read);

    lin.reset();
    byte[] small = new byte[5];

    assertEquals(3, Iterables.frequency(multiset, "a"));
    assertEquals(2, Iterables.frequency(multiset, "b"));
    assertEquals(1, Iterables.frequency(multiset, "c"));
    assertEquals(0, Iterables.frequency(multiset, "d"));
    assertEquals(0, Iterables.frequency(multiset, 4.2));
    assertEquals(0, Iterables.frequency(multiset, null));
  }

    multiset.add("foo", 2);
    multiset.add("bar");
    assertEquals(3, multiset.size());
    assertEquals(2, multiset.count("foo"));
    assertEquals("[foo x 2, bar]", multiset.toString());
  }

  public void testCreateFromIterable() {
    Multiset<String> multiset = TreeMultiset.create(Arrays.asList("foo", "bar", "foo"));
    assertEquals(3, multiset.size());
    assertEquals(2, multiset.count("foo"));

    assertEquals("b", cycle.next());
    assertTrue(cycle.hasNext());
    assertEquals("a", cycle.next());
    cycle.remove();
    assertEquals(Collections.singletonList("b"), iterable);
    assertTrue(cycle.hasNext());
    assertEquals("b", cycle.next());
    assertTrue(cycle.hasNext());
    assertEquals("b", cycle.next());
    cycle.remove();
    assertEquals(Collections.emptyList(), iterable);
    assertFalse(cycle.hasNext());