boolean contains(@Nonnull Version version);

    /**
     * Returns the upper boundary of this range, or {@code null} if none.
     */
    @Nullable
    Boundary getUpperBoundary();

    /**
     * Returns the lower boundary of this range, or {@code null} if none.
     */
    @Nullable
    Boundary getLowerBoundary();

    /**
     * {@return the string representation of this version}
     */
    @Nonnull
    @Override

import java.util.Comparator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.function.Function;
import java.util.stream.Collector;
import java.util.stream.Stream;
import org.jspecify.annotations.Nullable;

/**
 * A {@link ListMultimap} whose contents will never change, with many other important properties
 * detailed at {@link ImmutableCollection}.
 *
 * <p>See the Guava User Guide article on <a href=

  @Override
  public E takeLast() throws InterruptedException {
    return delegate().takeLast();
  }

  @Override
  public @Nullable E pollFirst(long timeout, TimeUnit unit) throws InterruptedException {
    return delegate().pollFirst(timeout, unit);
  }

  @Override
  public @Nullable E pollLast(long timeout, TimeUnit unit) throws InterruptedException {
    return delegate().pollLast(timeout, unit);
  }

  @Override

   * PeekingIterator#remove()} removes the same elements as the reference's iterator {@code
   * remove()}.
   */
  private static class PeekingIteratorTester<T extends @Nullable Object> extends IteratorTester<T> {
    private final Iterable<T> master;
    private @Nullable List<T> targetList;

    PeekingIteratorTester(Collection<T> master) {
      super(master.size() + 3, MODIFIABLE, master, IteratorTester.KnownOrder.KNOWN_ORDER);

    // The same element is not allowed in both forgetMeNot and skipMe, but duplicates are allowed in
    // either of them, up to the same multiplicity as the queue.
    private @Nullable Queue<E> forgetMeNot;
    private @Nullable List<E> skipMe;
    private @Nullable E lastFromForgetMeNot;
    private boolean canRemove;

    @Override
    public boolean hasNext() {
      checkModCount();
      nextNotInSkipMe(cursor + 1);

  }

  public void testCopyOf_nullArray() {
    assertThrows(NullPointerException.class, () -> copyOf((String[]) null));
  }

  public void testCopyOf_arrayContainingOnlyNull() {
    @Nullable String[] array = new @Nullable String[] {null};
    assertThrows(NullPointerException.class, () -> copyOf((String[]) array));
  }

  public void testCopyOf_collection_empty() {
    Collection<String> c = MinimalCollection.of();

      @Override
      protected char @Nullable [] escape(char c) {
        return replacementMap.get(c);
      }
    };
  }

  // A trivial non-optimized escaper for testing.
  static UnicodeEscaper createSimpleUnicodeEscaper(ImmutableMap<Integer, char[]> replacementMap) {
    return new UnicodeEscaper() {
      @Override
      protected char @Nullable [] escape(int cp) {
        return replacementMap.get(cp);

    public CustomScheduler() {}

    /** A callable class that can reschedule itself using a {@link CustomScheduler}. */
    private final class ReschedulableCallable implements Callable<@Nullable Void> {

      /** The underlying task. */
      private final Runnable wrappedRunnable;

      /** The executor on which this Callable will be scheduled. */
      private final ScheduledExecutorService executor;

  private final StatsCounter statsCounter;
  private final @Nullable RemovalListener<? super K, ? super V> removalListener;
  private final long maximumSize;

  CapacityEnforcingMap(
      int initialCapacity,
      float loadFactor,
      boolean accessOrder,
      long maximumSize,
      StatsCounter statsCounter,
      @Nullable RemovalListener<? super K, ? super V> removalListener) {

       * @param t the exception to set as the result of the computation.
       * @param finalState the state to transition to.
       */
      private boolean complete(@Nullable V v, @Nullable Throwable t, int finalState) {
        boolean doCompletion = compareAndSetState(RUNNING, COMPLETING);
        if (doCompletion) {
          // If this thread successfully transitioned to COMPLETING, set the value