*       instance each time they are called. The caller is responsible for ensuring that the
 *       returned writer is closed.
 *   <li><b>Convenience methods:</b> These are implementations of common operations that are
 *       typically implemented by opening a writer using one of the methods in the first category,
 *       doing something and finally closing the writer that was opened.
 * </ul>
 *

 *       worse, and possibly better, than creating a mutable collection and copying it.
 *   <li>Implementations generally do not cache hash codes. If your element or key type has a slow
 *       {@code hashCode} implementation, it should cache it itself.
 * </ul>
 *
 * <h4>Example usage</h4>
 *
 * <pre>{@code
 * class Foo {

  /**
   * Returns an early guess of the next response, used for policy on how an incoming request should
   * be received. The default implementation returns an empty response. Mischievous implementations
   * can return other values to test HTTP edge cases, such as unhappy socket policies or throttled
   * request bodies.
   */
  open fun peek(): MockResponse {

 * interface ListFactory {
 *   ...
 *   {@literal @}GwtCompatible(serializable = true)
 *   {@literal <E> List<E>} newArrayList(E... elements);
 * }
 * </pre>
 *
 * <p>The {@code newArrayList(E[])} method of all implementations of {@code ListFactory} is expected
 * to return a value with a GWT serializable type.
 *
 * <p>Note that a {@code GwtCompatible} type may have some {@link GwtIncompatible} methods.
 *
 * @author Charles Fry

import static com.google.common.base.Preconditions.checkState;

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;

/** Precondition checks useful in collection implementations. */
@GwtCompatible
@ElementTypesAreNonnullByDefault
final class CollectPreconditions {

  static void checkEntryNotNull(Object key, Object value) {
    if (key == null) {

import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * A type implemented by, or extended by maven plugins or extensions.
 * Maven plugins or extensions may provide implementations of those types which will be used by maven.
 * <p>
 * A type can be marked {@link Consumer} or {@link Provider} but not both. A type is assumed to be

/**
 * Provides similar behavior to {@link String#intern} for any immutable type. Common implementations
 * are available from the {@link Interners} class.
 *
 * <p>Note that {@code String.intern()} has some well-known performance limitations, and should
 * generally be avoided. Prefer {@link Interners#newWeakInterner} or another {@code Interner}
 * implementation even for {@code String} interning.
 *
 * @author Kevin Bourrillion
 * @since 3.0
 */

 */

package com.google.common.collect.testing.google;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.SetMultimap;

/**
 * A generator for {@code SetMultimap} implementations based on test data.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
public interface TestSetMultimapGenerator<K, V>

 * #get(Object, Callable)} or {@link #put(Object, Object)}, and are stored in the cache until either
 * evicted or manually invalidated. The common way to build instances is using {@link CacheBuilder}.
 *
 * <p>Implementations of this interface are expected to be thread-safe, and can be safely accessed
 * by multiple concurrent threads.
 *
 * @param <K> the type of the cache's keys, which are not permitted to be null

 */

package com.google.common.collect.testing.google;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.SetMultimap;

/**
 * A generator for {@code SetMultimap} implementations based on test data.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
public interface TestSetMultimapGenerator<K, V>