assertEquals(a, sortedMultiset.headMultiset(b.getElement(), OPEN).lastEntry());
    assertEquals(a, sortedMultiset.headMultiset(c.getElement(), OPEN).lastEntry());
  }

  @CollectionSize.Require(SEVERAL)
  public void testFloor() {
    resetWithHole();
    assertEquals(a, sortedMultiset.headMultiset(a.getElement(), CLOSED).lastEntry());

    assertEquals(a, sortedMultiset.headMultiset(b.getElement(), OPEN).lastEntry());
    assertEquals(a, sortedMultiset.headMultiset(c.getElement(), OPEN).lastEntry());
  }

  @CollectionSize.Require(SEVERAL)
  public void testFloor() {
    resetWithHole();
    assertEquals(a, sortedMultiset.headMultiset(a.getElement(), CLOSED).lastEntry());

    }
  }

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

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

    }
  }

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

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

          }
        }
        return false;
      }
      return true;
    }

    @Override
    public void remove() {
      checkState(lastEntry != null);
      LocalCache.this.remove(lastEntry.getKey(), lastEntry.getValue());
      lastEntry = null;
    }
  }

  /** KeyIterator build on top of EntryIterator. */
  final class KeyIterator implements Iterator<K> {
    private EntryIterator iterator;

      }
      if (succ == null) {
        lastEntry = pred;
      } else {
        succ.predecessorInValueSet = pred;
      }
    }

    private void deleteFromValueSet(ValueEntry<K, V> entry) {
      succeedsInValueSet(entry.predecessorInValueSet, entry.successorInValueSet);
    }

    private void appendToValueSet(ValueEntry<K, V> newEntry) {
      succeedsInValueSet(lastEntry, newEntry);
      lastEntry = newEntry;

    Entry<Cut<K>, RangeMapEntry<K, V>> lastEntry = entriesByLowerBound.lastEntry();
    // Either both are null or neither is, but we check both to satisfy the nullness checker.
    if (firstEntry == null || lastEntry == null) {
      throw new NoSuchElementException();
    }
    return Range.create(
        firstEntry.getValue().getKey().lowerBound, lastEntry.getValue().getKey().upperBound);
  }

        : null;
  }

  @Override
  public Range<C> span() {
    Entry<Cut<C>, Range<C>> firstEntry = rangesByLowerBound.firstEntry();
    Entry<Cut<C>, Range<C>> lastEntry = rangesByLowerBound.lastEntry();
    if (firstEntry == null || lastEntry == null) {
      /*
       * Either both are null or neither is: Either the set is empty, or it's not. But we check both
       * to make the nullness checker happy.
       */

      return (entry == null) ? null : wrapEntry(entry);
    }

    @Override
    public @Nullable Entry<K, Collection<V>> lastEntry() {
      Entry<K, Collection<V>> entry = sortedMap().lastEntry();
      return (entry == null) ? null : wrapEntry(entry);
    }

    @Override
    public @Nullable Entry<K, Collection<V>> pollFirstEntry() {