public void testCeiling() {
    resetWithHole();
    assertEquals(a, navigableMap.ceilingEntry(a.getKey()));
    assertEquals(a.getKey(), navigableMap.ceilingKey(a.getKey()));
    assertEquals(c, navigableMap.ceilingEntry(b.getKey()));
    assertEquals(c.getKey(), navigableMap.ceilingKey(b.getKey()));
    assertEquals(c, navigableMap.ceilingEntry(c.getKey()));
    assertEquals(c.getKey(), navigableMap.ceilingKey(c.getKey()));
  }

  public void testCeiling() {
    resetWithHole();
    assertEquals(a, navigableMap.ceilingEntry(a.getKey()));
    assertEquals(a.getKey(), navigableMap.ceilingKey(a.getKey()));
    assertEquals(c, navigableMap.ceilingEntry(b.getKey()));
    assertEquals(c.getKey(), navigableMap.ceilingKey(b.getKey()));
    assertEquals(c, navigableMap.ceilingEntry(c.getKey()));
    assertEquals(c.getKey(), navigableMap.ceilingKey(c.getKey()));
  }

  }

  @Override
  @CheckForNull
  public Entry<K, V> ceilingEntry(@ParametricNullness K key) {
    return delegate().ceilingEntry(key);
  }

  /**
   * A sensible definition of {@link #ceilingEntry} in terms of the {@code firstEntry()} of {@link
   * #tailMap(Object, boolean)}. If you override {@code tailMap}, you may wish to override {@code
   * ceilingEntry} to forward to this implementation.
   */
  @CheckForNull

  }

  @Override
  @CheckForNull
  public Entry<K, V> ceilingEntry(@ParametricNullness K key) {
    return delegate().ceilingEntry(key);
  }

  /**
   * A sensible definition of {@link #ceilingEntry} in terms of the {@code firstEntry()} of {@link
   * #tailMap(Object, boolean)}. If you override {@code tailMap}, you may wish to override {@code
   * ceilingEntry} to forward to this implementation.
   */
  @CheckForNull

    protected NavigableMap<K, V> delegate() {
      return (NavigableMap<K, V>) super.delegate();
    }

    @Override
    public @Nullable Entry<K, V> ceilingEntry(K key) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate().ceilingEntry(key);
    }

    @Override
    public @Nullable K ceilingKey(K key) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate().ceilingKey(key);

  }

  @Override
  @CheckForNull
  public Entry<K, V> floorEntry(@ParametricNullness K key) {
    return headMap(key, true).lastEntry();
  }

  @Override
  @CheckForNull
  public Entry<K, V> ceilingEntry(@ParametricNullness K key) {
    return tailMap(key, true).firstEntry();
  }

  @Override
  @CheckForNull
  public Entry<K, V> higherEntry(@ParametricNullness K key) {

    if (delegate == null) {
      throw new NullPointerException();
    }
    for (K k : keySet()) {
      checkValid(k);
    }
  }

  @Override
  public @Nullable Entry<K, V> ceilingEntry(K key) {
    return delegate.ceilingEntry(checkValid(key));
  }

  @Override
  public @Nullable K ceilingKey(K key) {
    return delegate.ceilingKey(checkValid(key));
  }

  @Override
  public void clear() {

    if (delegate == null) {
      throw new NullPointerException();
    }
    for (K k : keySet()) {
      checkValid(k);
    }
  }

  @Override
  public @Nullable Entry<K, V> ceilingEntry(K key) {
    return delegate.ceilingEntry(checkValid(key));
  }

  @Override
  public @Nullable K ceilingKey(K key) {
    return delegate.ceilingKey(checkValid(key));
  }

  @Override
  public void clear() {

  }

  @Override
  @CheckForNull
  public Entry<K, V> floorEntry(@ParametricNullness K key) {
    return headMap(key, true).lastEntry();
  }

  @Override
  @CheckForNull
  public Entry<K, V> ceilingEntry(@ParametricNullness K key) {
    return tailMap(key, true).firstEntry();
  }

  @Override
  @CheckForNull
  public Entry<K, V> higherEntry(@ParametricNullness K key) {

    }
  }

  @Override
  public boolean intersects(Range<C> range) {
    checkNotNull(range);
    Entry<Cut<C>, Range<C>> ceilingEntry = rangesByLowerBound.ceilingEntry(range.lowerBound);
    if (ceilingEntry != null
        && ceilingEntry.getValue().isConnected(range)
        && !ceilingEntry.getValue().intersection(range).isEmpty()) {
      return true;
    }