import org.jspecify.annotations.Nullable;

/**
 * Utilities for dealing with sorted collections of all types.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
final class SortedIterables {
  private SortedIterables() {}

  /**
   * Returns {@code true} if {@code elements} is a sorted collection using an ordering equivalent to
   * {@code comparator}.
   */

import org.jspecify.annotations.NullMarked;

/**
 * Unit tests for {@code SortedIterables}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@NullMarked
public class SortedIterablesTest extends TestCase {
  public void testSameComparator() {
    assertTrue(SortedIterables.hasSameComparator(Ordering.natural(), Sets.newTreeSet()));
    assertTrue(SortedIterables.hasSameComparator(Ordering.natural(), Maps.newTreeMap().keySet()));

   */
  public static <E> ImmutableSortedSet<E> copyOf(
      Comparator<? super E> comparator, Iterable<? extends E> elements) {
    checkNotNull(comparator);
    boolean hasSameComparator = SortedIterables.hasSameComparator(comparator, elements);

    if (hasSameComparator && (elements instanceof ImmutableSortedSet)) {
      @SuppressWarnings("unchecked")