}

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

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

  }

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

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

    }
  }

  @Override
  public @Nullable Entry<K, V> lowerEntry(@ParametricNullness K key) {
    return headMap(key, false).lastEntry();
  }

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

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

  public void testFloor() {
    resetWithHole();
    assertEquals(a, navigableMap.floorEntry(a.getKey()));
    assertEquals(a.getKey(), navigableMap.floorKey(a.getKey()));
    assertEquals(a, navigableMap.floorEntry(b.getKey()));
    assertEquals(a.getKey(), navigableMap.floorKey(b.getKey()));
    assertEquals(c, navigableMap.floorEntry(c.getKey()));
    assertEquals(c.getKey(), navigableMap.floorKey(c.getKey()));
  }

    }
  }

  @Override
  public @Nullable Entry<K, V> lowerEntry(@ParametricNullness K key) {
    return headMap(key, false).lastEntry();
  }

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

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

    return (entry == null) ? null : entry.getValue();
  }

  @Override
  public @Nullable Entry<Range<K>, V> getEntry(K key) {
    Entry<Cut<K>, RangeMapEntry<K, V>> mapEntry =
        entriesByLowerBound.floorEntry(Cut.belowValue(key));
    if (mapEntry != null && mapEntry.getValue().contains(key)) {
      return mapEntry.getValue();
    } else {
      return null;
    }
  }

  @Override

    return delegate.firstEntry();
  }

  @Override
  public K firstKey() {
    return delegate.firstKey();
  }

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

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

  @Override
  public @Nullable V get(Object key) {

    return delegate.firstEntry();
  }

  @Override
  public K firstKey() {
    return delegate.firstKey();
  }

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

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

  @Override
  public @Nullable V get(Object key) {

    return (entry == null) ? null : entry.getValue();
  }

  @Override
  public @Nullable Entry<Range<K>, V> getEntry(K key) {
    Entry<Cut<K>, RangeMapEntry<K, V>> mapEntry =
        entriesByLowerBound.floorEntry(Cut.belowValue(key));
    if (mapEntry != null && mapEntry.getValue().contains(key)) {
      return mapEntry.getValue();
    } else {
      return null;
    }
  }

  @Override

    for (K key : keysToTest) {
      assertEquals(expected.lowerEntry(key), navigableMap.lowerEntry(key));
      assertEquals(expected.floorEntry(key), navigableMap.floorEntry(key));
      assertEquals(expected.ceilingEntry(key), navigableMap.ceilingEntry(key));
      assertEquals(expected.higherEntry(key), navigableMap.higherEntry(key));