}
  }

  @Override
  public @Nullable Entry<E> firstEntry() {
    return delegate().firstEntry();
  }

  /**
   * A sensible definition of {@link #firstEntry()} in terms of {@code entrySet().iterator()}.
   *
   * <p>If you override {@link #entrySet()}, you may wish to override {@link #firstEntry()} to
   * forward to this implementation.
   */

    assertEquals(c, sortedMultiset.tailMultiset(b.getElement(), CLOSED).firstEntry());
    assertEquals(c, sortedMultiset.tailMultiset(c.getElement(), CLOSED).firstEntry());
  }

  @CollectionSize.Require(SEVERAL)
  public void testHigher() {
    resetWithHole();
    assertEquals(c, sortedMultiset.tailMultiset(a.getElement(), OPEN).firstEntry());

    }
  }

  @Override
  public @Nullable Entry<E> firstEntry() {
    return delegate().firstEntry();
  }

  /**
   * A sensible definition of {@link #firstEntry()} in terms of {@code entrySet().iterator()}.
   *
   * <p>If you override {@link #entrySet()}, you may wish to override {@link #firstEntry()} to
   * forward to this implementation.
   */

    assertEquals(c, sortedMultiset.tailMultiset(b.getElement(), CLOSED).firstEntry());
    assertEquals(c, sortedMultiset.tailMultiset(c.getElement(), CLOSED).firstEntry());
  }

  @CollectionSize.Require(SEVERAL)
  public void testHigher() {
    resetWithHole();
    assertEquals(c, sortedMultiset.tailMultiset(a.getElement(), OPEN).firstEntry());

    return keyOrNull(higherEntry(key));
  }

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

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

    return keyOrNull(higherEntry(key));
  }

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

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

  }

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

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

  @Override
  public @Nullable K lowerKey(@ParametricNullness K key) {
    return Maps.keyOrNull(lowerEntry(key));
  }

    }
    Iterator<Entry<K, V>> iterator = map.entrySet().iterator();
    Entry<K, V> firstEntry = iterator.next();
    Entry<K, V> secondEntry = iterator.next();
    K key = secondEntry.getKey();
    SortedMap<K, V> subMap = map.tailMap(key);
    subMap.remove(key);
    assertNull(subMap.remove(firstEntry.getKey()));
    assertEquals(map.size(), oldSize - 1);
    assertFalse(map.containsKey(key));

    }
    Iterator<Entry<K, V>> iterator = map.entrySet().iterator();
    Entry<K, V> firstEntry = iterator.next();
    Entry<K, V> secondEntry = iterator.next();
    K key = secondEntry.getKey();
    SortedMap<K, V> subMap = map.tailMap(key);
    subMap.remove(key);
    assertNull(subMap.remove(firstEntry.getKey()));
    assertEquals(map.size(), oldSize - 1);
    assertFalse(map.containsKey(key));

  }

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

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

  @Override
  public @Nullable K lowerKey(@ParametricNullness K key) {
    return Maps.keyOrNull(lowerEntry(key));
  }