assertEquals(ImmutableSortedSet.of(4, 6, 8, 10), Sets.subSet(set, Range.atLeast(4)));
    assertEquals(ImmutableSortedSet.of(8, 10), Sets.subSet(set, Range.atLeast(7)));
    assertEquals(empty, Sets.subSet(set, Range.atLeast(20)));

    assertEquals(set, Sets.subSet(set, Range.greaterThan(0)));
    assertEquals(ImmutableSortedSet.of(6, 8, 10), Sets.subSet(set, Range.greaterThan(4)));

  }

  @Override
  public NavigableSet<E> subSet(
      E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
    return new SafeTreeSet<>(
        delegate.subSet(
            checkValid(fromElement), fromInclusive, checkValid(toElement), toInclusive));
  }

  @Override
  public SortedSet<E> subSet(E fromElement, E toElement) {
    return subSet(fromElement, true, toElement, false);
  }

  }

  @Override
  @ParametricNullness
  public E last() {
    return delegate().last();
  }

  @Override
  public SortedSet<E> subSet(@ParametricNullness E fromElement, @ParametricNullness E toElement) {
    return delegate().subSet(fromElement, toElement);
  }

  @Override
  public SortedSet<E> tailSet(@ParametricNullness E fromElement) {
    return delegate().tailSet(fromElement);
  }

    assertTrue(
        "containsAll(empty) should return true", collection.containsAll(MinimalCollection.of()));
  }

  @CollectionSize.Require(absent = ZERO)
  public void testContainsAll_subset() {
    assertTrue(
        "containsAll(subset) should return true",
        collection.containsAll(MinimalCollection.of(e0())));
  }

  public void testContainsAll_sameElements() {
    assertTrue(

  }

  /**
   * {@inheritDoc}
   *
   * <p>This method returns a serializable {@code ImmutableSortedSet}.
   *
   * <p>The {@link SortedSet#subSet} documentation states that a subset of a subset throws an {@link
   * IllegalArgumentException} if passed a {@code fromElement} smaller than an earlier {@code
   * fromElement}. However, this method doesn't throw an exception in that situation, but instead

  public void testRetainAll_supersetUnsupported() {
    expectReturnsFalseOrThrows(superset);
    expectUnchanged();
  }

  // retainAll(subset)

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testRetainAll_subset() {
    expectReturnsTrue(nonEmptyProperSubset);
    expectContents(nonEmptyProperSubset.toRetain);
  }

   * have started execution. This applies also to tasks given to {@code invokeAll} or {@code
   * invokeAny} which are pending serial execution, even the subset of the tasks that have not yet
   * started execution. It is unclear from the {@code ExecutorService} specification if these should
   * be included, and it's much easier to implement the interpretation that they not be. Finally, a

 * the License.
 */

package com.google.common.base;

import com.google.common.annotations.GwtCompatible;

/**
 * The subset of the {@link java.util.regex.Pattern} API which is used by this package, and also
 * shared with the {@code re2j} library. For internal use only. Please refer to the {@code Pattern}
 * javadoc for details.
 */
@GwtCompatible

 *
 * @author Hayward Chan
 */
@ElementTypesAreNonnullByDefault
final class RegularImmutableSortedSet<E> extends ImmutableSortedSet<E> {

  /** true if this set is a subset of another immutable sorted set. */
  final boolean isSubset;

  private @Nullable Comparator<E> unusedComparatorForSerialization;
  private @Nullable E unusedElementForSerialization;

 * the License.
 */

package com.google.common.base;

import com.google.common.annotations.GwtCompatible;

/**
 * The subset of the {@link java.util.regex.Pattern} API which is used by this package, and also
 * shared with the {@code re2j} library. For internal use only. Please refer to the {@code Pattern}
 * javadoc for details.
 */
@GwtCompatible