/** Constructor for use by subclasses. */
    public StandardElementSet() {
      super(ForwardingSortedMultiset.this);
    }
  }

  @Override
  public Comparator<? super E> comparator() {
    return delegate().comparator();
  }

  @Override
  public SortedMultiset<E> descendingMultiset() {
    return delegate().descendingMultiset();
  }

  /**

 * returned.
 *
 * <p>All default instances returned by {@link #get} are generics-safe. Clients won't get type
 * errors for using {@code get(Comparator.class)} as a {@code Comparator<Foo>}, for example.
 * Immutable empty instances are returned for collection types; {@code ""} for string; {@code 0} for

import com.google.caliper.Benchmark;
import com.google.caliper.Param;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Random;
import org.jspecify.annotations.NullUnmarked;

/**
 * A benchmark to determine the overhead of sorting with {@link Ordering#from(Comparator)}, or with
 * {@link Ordering#natural()}, as opposed to using the inlined {@link Arrays#sort(Object[])}

 * invoke methods, they invoke methods on the {@code ForwardingNavigableSet}.
 *
 * <p>Each of the {@code standard} methods uses the set's comparator (or the natural ordering of the
 * elements, if there is no comparator) to test element equality. As a result, if the comparator is
 * not consistent with equals, some of the standard implementations may violate the {@code Set}
 * contract.
 *

    }

    @Override
    SortedSet<R> createKeySet() {
      return new Maps.SortedKeySet<>(this);
    }

    @Override
    public @Nullable Comparator<? super R> comparator() {
      return sortedBackingMap().comparator();
    }

    @Override
    public R firstKey() {
      return sortedBackingMap().firstKey();
    }

    @Override
    public R lastKey() {

      return standardTailSet(fromElement);
    }

    @SuppressWarnings("unchecked")
    @Override
    public Comparator<? super E> comparator() {
      Comparator<? super E> forwardComparator = forward.comparator();
      if (forwardComparator == null) {
        return (Comparator) Ordering.natural().reverse();
      } else {
        return reverse(forwardComparator);
      }
    }

      map.put(entry.getKey(), entry.getValue());
    }
    return map;
  }

  static <T> Comparator<T> arbitraryNullFriendlyComparator() {
    return new NullFriendlyComparator<>();
  }

  private static final class NullFriendlyComparator<T> implements Comparator<T>, Serializable {
    @Override
    public int compare(T left, T right) {

   * FluentIterable} in the order specified by {@code comparator}. To produce an {@code
   * ImmutableList} sorted by its natural ordering, use {@code toSortedList(Ordering.natural())}.
   *
   * <p><b>{@code Stream} equivalent:</b> pass {@link ImmutableList#toImmutableList} to {@code
   * stream.sorted(comparator).collect()}.
   *
   * @param comparator the function by which to sort list elements

   * FluentIterable} in the order specified by {@code comparator}. To produce an {@code
   * ImmutableList} sorted by its natural ordering, use {@code toSortedList(Ordering.natural())}.
   *
   * <p><b>{@code Stream} equivalent:</b> pass {@link ImmutableList#toImmutableList} to {@code
   * stream.sorted(comparator).collect()}.
   *
   * @param comparator the function by which to sort list elements

     * empty or a partial view?
     *
     * Related: Should methods that do accept a comparator (like fromMapEntries, or like this one if
     * we were to choose to *preserve* an input comparator) return not the generic empty of()
     * instance but instead an empty ImmutableSetMultimap instance with the requested
     * valueComparator, since the comparator is visible when users call `get` on a key that's not
     * present?
     */