} while (chars.contains(c));
      chars.add(c);
    }
    char[] retValue = new char[chars.size()];
    int i = 0;
    for (char c : chars) {
      retValue[i++] = c;
    }
    Arrays.sort(retValue);
    return retValue;
  }

  public void testToString() {
    assertToStringWorks(CharMatcher.anyOf(""), "CharMatcher.none()");

            .isSameInstanceAs(entry.getValue());
        Object newKey = new Object();
        assertThat(cache.asMap().putIfAbsent(newKey, entry.getValue())).isNull();
        // this getUnchecked() call shouldn't be a cache miss; verified below
        assertThat(cache.getUnchecked(entry.getKey())).isEqualTo(entry.getValue());
        assertThat(cache.getUnchecked(newKey)).isEqualTo(entry.getValue());
        // don't let the new entry get GCed

    /** Clears the reference queues used by this segment, if any. */
    void maybeClearReferenceQueues() {}

    /** Sets the value of the given {@code entry}. */
    void setValue(E entry, V value) {
      this.map.entryHelper.setValue(self(), entry, value);
    }

    /** Returns a copy of the given {@code entry}. */
    @Nullable E copyEntry(E original, E newNext) {

    assertThat(entry.getValue()).isEqualTo("World");
    assertTrue(iter.hasNext());

    entry = iter.next();
    assertThat(entry.getKey()).isEqualTo("first");
    assertThat(entry.getValue()).isEqualTo("second");
    assertTrue(iter.hasNext());

    entry = iter.next();
    assertThat(entry.getKey()).isEqualTo("polygene");
    assertThat(entry.getValue()).isEqualTo("lubricants");

    /** Clears the reference queues used by this segment, if any. */
    void maybeClearReferenceQueues() {}

    /** Sets the value of the given {@code entry}. */
    void setValue(E entry, V value) {
      this.map.entryHelper.setValue(self(), entry, value);
    }

    /** Returns a copy of the given {@code entry}. */
    @Nullable E copyEntry(E original, E newNext) {

    }

    @Override
    public V getValue() {
      assertTrue(Thread.holdsLock(mutex));
      return super.getValue();
    }

    @Override
    public int hashCode() {
      assertTrue(Thread.holdsLock(mutex));
      return super.hashCode();
    }

    @Override
    public V setValue(V value) {
      assertTrue(Thread.holdsLock(mutex));
      return super.setValue(value);
    }

      assertEquals(2 * i, (int) inverse.get(2 * i - 1));
    }
    Set<Entry<Integer, Integer>> entries = bimap.entrySet();
    for (Entry<Integer, Integer> entry : entries) {
      entry.setValue(entry.getValue() + 2 * N);
    }
    for (int i = 0; i < N; i++) {
      assertEquals(2 * N + 2 * i - 1, (int) bimap.get(2 * i));
    }
  }

  public void testBiMapEntrySetIteratorRemove() {

                        @Override
                        public String setValue(String value) {
                          checkNotNull(value);
                          return next.setValue(value);
                        }

                        @Override
                        public String getValue() {
                          return next.getValue();
                        }

                        @Override

                        @Override
                        public String setValue(String value) {
                          checkNotNull(value);
                          return next.setValue(value);
                        }

                        @Override
                        public String getValue() {
                          return next.getValue();
                        }

                        @Override

      assertEquals(2 * i, (int) inverse.get(2 * i - 1));
    }
    Set<Entry<Integer, Integer>> entries = bimap.entrySet();
    for (Entry<Integer, Integer> entry : entries) {
      entry.setValue(entry.getValue() + 2 * N);
    }
    for (int i = 0; i < N; i++) {
      assertEquals(2 * N + 2 * i - 1, (int) bimap.get(2 * i));
    }
  }

  public void testBiMapEntrySetIteratorRemove() {