@SuppressWarnings("unchecked") // The natural-ordered empty set supports all types.
      RegularImmutableSortedSet<E> result =
          (RegularImmutableSortedSet<E>) RegularImmutableSortedSet.NATURAL_EMPTY_SET;
      return result;
    } else {
      return new RegularImmutableSortedSet<>(ImmutableList.of(), comparator);
    }
  }

  /**
   * Returns the empty immutable sorted set.
   *

    }

    @LazyInit @CheckForNull transient Set<E> elementSet;

    Set<E> createElementSet() {
      return Collections.<E>unmodifiableSet(delegate.elementSet());
    }

    @Override
    public Set<E> elementSet() {
      Set<E> es = elementSet;
      return (es == null) ? elementSet = createElementSet() : es;
    }

    @LazyInit @CheckForNull transient Set<Multiset.Entry<E>> entrySet;

      K key = entry.getKey();
      Collection<? extends V> values = entry.getValue();
      ImmutableSet<V> set = valueSet(valueComparator, values);
      if (!set.isEmpty()) {
        builder.put(key, set);
        size += set.size();
      }
    }

    return new ImmutableSetMultimap<>(builder.buildOrThrow(), size, valueComparator);
  }

  /**

        with:
          access_token: ${{ github.token }}
      - name: 'Check out repository'
        uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b # v4.1.4
      - name: 'Set up JDK ${{ matrix.java }}'
        uses: actions/setup-java@99b8673ff64fbf99d8d325f52d9a5bdedb8483e9 # v4.2.1

        with:
          java-version: ${{ matrix.java }}
          distribution: 'zulu'
          cache: 'maven'

import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
import java.util.Spliterator;
import java.util.Spliterator.OfPrimitive;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Supplier;

  public static int frequency(Iterable<?> iterable, @CheckForNull Object element) {
    if ((iterable instanceof Multiset)) {
      return ((Multiset<?>) iterable).count(element);
    } else if ((iterable instanceof Set)) {
      return ((Set<?>) iterable).contains(element) ? 1 : 0;
    }
    return Iterators.frequency(iterable.iterator(), element);
  }

  /**

   * range set (such as {@code ImmutableRangeSet.of(Range.greaterThan(0))}). Certain operations on
   * such a set can be performed efficiently, but others (such as {@link Set#hashCode} or {@link
   * Collections#frequency}) can cause major performance problems.
   *
   * <p>The returned set's {@link Object#toString} method returns a shorthand form of the set's
   * contents, such as {@code "[1..100]}"}.
   *

      }
    }
    // If we get here then the Listener TOMBSTONE was set, which means the future is done, call
    // the listener.
    executeListener(listener, executor);
  }

  /**
   * Sets the result of this {@code Future} unless this {@code Future} has already been cancelled or
   * set (including {@linkplain #setFuture set asynchronously}). When a call to this method returns,

   * set. The order in which these subsets appear in the outer set is undefined. Note that the power
   * set of the empty set is not the empty set, but a one-element set containing the empty set.
   *
   * <p>The returned set and its constituent sets use {@code equals} to decide whether two elements
   * are identical, even if the input set uses a different concept of equivalence.
   *

    return (index == -1) ? null : valueList.get(index);
  }

  @Override
  boolean isPartialView() {
    return keySet.isPartialView() || valueList.isPartialView();
  }

  /** Returns an immutable set of the mappings in this map, sorted by the key ordering. */
  @Override
  public ImmutableSet<Entry<K, V>> entrySet() {
    return super.entrySet();
  }

  @Override
  ImmutableSet<Entry<K, V>> createEntrySet() {