@GwtCompatible
interface SortedIterable<T extends @Nullable Object> extends Iterable<T> {
  /**
   * Returns the {@code Comparator} by which the elements of this iterable are ordered, or {@code
   * Ordering.natural()} if the elements are ordered by their natural ordering.
   */
  Comparator<? super T> comparator();

  /**
   * Returns an iterator over elements of type {@code T}. The elements are returned in nondecreasing

import static java.util.Arrays.asList;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.ImmutableSortedMap;
import com.google.common.collect.Ordering;
import com.google.common.collect.testing.SampleElements;
import com.google.common.collect.testing.TestListGenerator;
import com.google.common.collect.testing.TestStringListGenerator;

import com.google.common.annotations.J2ktIncompatible;
import java.io.Serializable;
import java.util.Comparator;
import org.jspecify.annotations.Nullable;

/** An ordering for a pre-existing comparator. */
@GwtCompatible
final class ComparatorOrdering<T extends @Nullable Object> extends Ordering<T>
    implements Serializable {
  final Comparator<T> comparator;

  ComparatorOrdering(Comparator<T> comparator) {

import com.google.common.annotations.GwtCompatible;
import java.util.List;
import java.util.SortedSet;
import org.jspecify.annotations.NullMarked;

/**
 * Create string sets for testing collections that are sorted by natural ordering.
 *
 * @author Jared Levy
 */
@GwtCompatible
@NullMarked
public abstract class TestStringSortedSetGenerator extends TestStringSetGenerator
    implements TestSortedSetGenerator<String> {

  @Override

    super(true, true, true);
  }

  private TreeMultimap<String, Integer> createMultimap() {
    TreeMultimap<String, Integer> multimap =
        TreeMultimap.create(
            Ordering.<String>natural().nullsFirst(), Ordering.<Integer>natural().nullsFirst());
    multimap.put("a", -1);
    multimap.put("a", -3);
    multimap.put("z", -2);
    return multimap;
  }

  @Override

                    return ImmutableSortedMultiset.copyOf(elements);
                  }

                  @Override
                  public List<String> order(List<String> insertionOrder) {
                    return Ordering.natural().sortedCopy(insertionOrder);
                  }
                })
            .named("ImmutableSortedMultiset")
            .withFeatures(
                CollectionSize.ANY,

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.graph;

import com.google.common.collect.Ordering;
import java.util.Arrays;
import java.util.Collection;
import org.jspecify.annotations.NullUnmarked;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.graph;

import com.google.common.collect.Ordering;
import java.util.Arrays;
import java.util.Collection;
import org.jspecify.annotations.NullUnmarked;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.graph;

import com.google.common.collect.Ordering;
import java.util.Arrays;
import java.util.Collection;
import org.jspecify.annotations.NullUnmarked;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;

  public void testNullPointers() {
    new NullPointerTester().testAllPublicStaticMethods(ImmutableSortedSet.class);
  }

  public void testEmpty_comparator() {
    SortedSet<String> set = of();
    assertSame(Ordering.natural(), set.comparator());
  }

  public void testEmpty_headSet() {
    SortedSet<String> set = of();
    assertSame(set, set.headSet("c"));
  }

  public void testEmpty_tailSet() {