*
 * <h3>Relationship to {@code Ordering}</h3>
 *
 * <p>In light of the significant enhancements to {@code Comparator} in Java 8, the overwhelming
 * majority of usages of {@code Ordering} can be written using only built-in JDK APIs. This class is
 * intended to "fill the gap" and provide those features of {@code Ordering} not already provided by
 * the JDK.
 *
 * @since 21.0
 * @author Louis Wasserman
 */
@GwtCompatible

   *     by subsequent {@code get()} calls
   * @throws IllegalArgumentException if {@code duration} is not positive
   * @since 33.1.0
   */
  @Beta // only until we're confident that Java 8+ APIs are safe for our Android users
  @J2ktIncompatible
  @GwtIncompatible // java.time.Duration
  @SuppressWarnings("Java7ApiChecker") // no more dangerous that wherever the user got the Duration
  @IgnoreJRERequirement

 *
 * <ul>
 *   <li>Memory footprint has a fixed overhead (about 24 bytes per instance).
 *   <li><i>Some</i> construction use cases force the data to be copied (though several construction
 *       APIs are offered that don't).
 *   <li>Can't be passed directly to methods that expect {@code int[]} (though the most common
 *       utilities do have replacements here).
 *   <li>Dependency on {@code com.google.common} / Guava.

 *
 * <ul>
 *   <li>Memory footprint has a fixed overhead (about 24 bytes per instance).
 *   <li><i>Some</i> construction use cases force the data to be copied (though several construction
 *       APIs are offered that don't).
 *   <li>Can't be passed directly to methods that expect {@code double[]} (though the most common
 *       utilities do have replacements here).
 *   <li>Dependency on {@code com.google.common} / Guava.

@GwtCompatible(emulated = true)
@ReflectionSupport(value = ReflectionSupport.Level.FULL)
@ElementTypesAreNonnullByDefault
// Some Android 5.0.x Samsung devices have bugs in JDK reflection APIs that cause
// getDeclaredField to throw a NoSuchFieldException when the field is definitely there.
// Since this class only needs CAS on one field, we can avoid this bug by extending AtomicReference

/** Collectors utilities for {@code common.collect} internals. */
@GwtCompatible
@ElementTypesAreNonnullByDefault
@SuppressWarnings({"AndroidJdkLibsChecker", "Java7ApiChecker"})
@IgnoreJRERequirement // used only from APIs with Java 8 types in them
// (not used publicly by guava-android as of this writing, but we include it in the jar as a test)
final class CollectCollectors {

   * Returns a default thread factory used to create new threads.
   *
   * <p>When running on AppEngine with access to <a
   * href="https://cloud.google.com/appengine/docs/standard/java/javadoc/">AppEngine legacy
   * APIs</a>, this method returns {@code ThreadManager.currentRequestThreadFactory()}. Otherwise,
   * it returns {@link Executors#defaultThreadFactory()}.
   *
   * @since 14.0
   */
  @J2ktIncompatible

                   If we're building with JDK8, then clearly we're sticking to
                   JDK8 APIs. However, I assume (but did not confirm) that we'd
                   have the same issue with our -android builds, which need
                   animal-sniffer so that they can check that we're sticking to
                   JDK6-like APIs.

                   So instead, we use javac9, which doesn't lead to this error.
              -->

   * (In other words, this method must allocate a new array). The caller is thus free to modify the
   * returned array.
   *
   * <p>This method acts as bridge between array-based and collection-based APIs.
   *
   * @return an array containing all of the elements in this queue
   */
  @CanIgnoreReturnValue
  @Override
  public Object[] toArray() {
    final E[] items = this.items;

 *
 * <h3>Relationship to {@code Ordering}</h3>
 *
 * <p>In light of the significant enhancements to {@code Comparator} in Java 8, the overwhelming
 * majority of usages of {@code Ordering} can be written using only built-in JDK APIs. This class is
 * intended to "fill the gap" and provide those features of {@code Ordering} not already provided by
 * the JDK.
 *
 * @since 21.0
 * @author Louis Wasserman
 */
@GwtCompatible