* for this entry is one, this is simply the string representation of the corresponding element.
     * Otherwise, it is the string representation of the element, followed by the three characters
     * {@code " x "} (space, letter x, space), followed by the count.
     */
    @Override
    String toString();
  }

  // Comparison and hashing

  /**

  private static final int BUFFER_SIZE = 8192;

  /** Creates a new byte array for buffering reads or writes. */
  static byte[] createBuffer() {
    return new byte[BUFFER_SIZE];
  }

  /**
   * There are three methods to implement {@link FileChannel#transferTo(long, long,
   * WritableByteChannel)}:
   *
   * <ol>
   *   <li>Use sendfile(2) or equivalent. Requires that both the input channel and the output

    Ordering<Number> c = objects.compound(numbers);

    Ordering<Integer> d = numbers.compound(integers);
    Ordering<Integer> e = integers.compound(numbers);

    // This works with three levels too (IDEA falsely reports errors as noted
    // below. Both javac and eclipse handle these cases correctly.)

    Ordering<Number> f = numbers.compound(objects).compound(objects); // bad IDEA

    Ordering<Number> c = objects.compound(numbers);

    Ordering<Integer> d = numbers.compound(integers);
    Ordering<Integer> e = integers.compound(numbers);

    // This works with three levels too (IDEA falsely reports errors as noted
    // below. Both javac and eclipse handle these cases correctly.)

    Ordering<Number> f = numbers.compound(objects).compound(objects); // bad IDEA

    assertFalse(map.containsValue(one));
    Object three = new Object();
    assertTrue(map.replace(one, two, three));
    assertTrue(map.remove(one, three));
    assertFalse(map.containsKey(one));
    assertFalse(map.containsValue(one));
    assertNull(map.putIfAbsent(two, three));
    assertSame(three, map.remove(two));
    assertNull(map.put(three, one));
    assertNull(map.put(one, two));

    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",

    @Override
    public String toString() {
      return "CharMatcher.anyOf(\"" + showCharacter(match1) + showCharacter(match2) + "\")";
    }
  }

  /** Implementation of {@link #anyOf(CharSequence)} for three or more characters. */
  private static final class AnyOf extends CharMatcher {

    private final char[] chars;

    public AnyOf(CharSequence chars) {
      this.chars = chars.toString().toCharArray();

  // 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

    unfiltered.put("two", 2);
    unfiltered.put("three", 3);
    unfiltered.put("four", 4);
    assertEquals(ImmutableMap.of("two", 2, "three", 3, "four", 4), unfiltered);
    assertEquals(ImmutableMap.of("three", 3, "four", 4), filtered);

    unfiltered.remove("three");
    assertEquals(ImmutableMap.of("two", 2, "four", 4), unfiltered);

    unfiltered.put("two", 2);
    unfiltered.put("three", 3);
    unfiltered.put("four", 4);
    assertEquals(ImmutableMap.of("two", 2, "three", 3, "four", 4), unfiltered);
    assertEquals(ImmutableMap.of("three", 3, "four", 4), filtered);

    unfiltered.remove("three");
    assertEquals(ImmutableMap.of("two", 2, "four", 4), unfiltered);