* entries may be counted in {@link Cache#size}, but will never be visible to read or write
 * operations.
 *
 * <p>Certain cache configurations will result in the accrual of periodic maintenance tasks which
 * will be performed during write operations, or during occasional read operations in the absence of
 * writes. The {@link Cache#cleanUp} method of the returned cache will also perform maintenance, but

 *       typically because the type forbids nullable type arguments: For example, {@code
 *       ImmutableList.get} returns {@code E}, but that value is never {@code null}. (Accordingly,
 *       {@code ImmutableList} is declared to forbid {@code ImmutableList<@Nullable String>}.)
 *   <li>methods whose return type is a type variable but which can return {@code null} regardless

 *       typically because the type forbids nullable type arguments: For example, {@code
 *       ImmutableList.get} returns {@code E}, but that value is never {@code null}. (Accordingly,
 *       {@code ImmutableList} is declared to forbid {@code ImmutableList<@Nullable String>}.)
 *   <li>methods whose return type is a type variable but which can return {@code null} regardless

 *       typically because the type forbids nullable type arguments: For example, {@code
 *       ImmutableList.get} returns {@code E}, but that value is never {@code null}. (Accordingly,
 *       {@code ImmutableList} is declared to forbid {@code ImmutableList<@Nullable String>}.)
 *   <li>methods whose return type is a type variable but which can return {@code null} regardless

 * Futures#transform(ListenableFuture, com.google.common.base.Function, Executor) Futures.transform}
 * (or {@link FluentFuture#transform(com.google.common.base.Function, Executor)
 * FluentFuture.transform}), but you will often find it easier to use a framework. Frameworks
 * automate the process, often adding features like monitoring, debugging, and cancellation.
 * Examples of frameworks include:
 *
 * <ul>

 * Futures#transform(ListenableFuture, com.google.common.base.Function, Executor) Futures.transform}
 * (or {@link FluentFuture#transform(com.google.common.base.Function, Executor)
 * FluentFuture.transform}), but you will often find it easier to use a framework. Frameworks
 * automate the process, often adding features like monitoring, debugging, and cancellation.
 * Examples of frameworks include:
 *
 * <ul>

    }
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testReplaceEntry_unsupportedAbsentKey() {
    try {
      getMap().replace(k3(), v3(), v4());
    } catch (UnsupportedOperationException tolerated) {
      // the operation would be a no-op, so exceptions are allowed but not required
    }
    expectUnchanged();

import java.util.Iterator;
import java.util.List;
import java.util.SortedSet;
import java.util.stream.Stream;
import org.jspecify.annotations.NonNull;
import org.jspecify.annotations.Nullable;

/**
 * A discouraged (but not deprecated) precursor to Java's superior {@link Stream} library.
 *
 * <p>The following types of methods are provided:
 *
 * <ul>
 *   <li>chaining methods which return a new {@code FluentIterable} based in some way on the

    )
    assertThat(webSocket.close(1000, null)).isFalse()
  }

  /**
   * There's no read timeout when reading the first byte of a new frame. But as soon as we start
   * reading a frame we enable the read timeout. In this test we have the server returning the first
   * byte of a frame but no more frames.
   */
  @Test
  fun readTimeoutAppliesWithinFrames() {
    webServer.dispatcher =
      object : Dispatcher() {

 * @since 2.0
 */
@GwtCompatible
public final class Predicates {

  /**
   * Returns a predicate that always evaluates to {@code true}.
   *
   * <p><b>Discouraged:</b> Prefer using {@code x -> true}, but note that lambdas do not have
   * human-readable {@link #toString()} representations and are not serializable.
   */
  public static <T extends @Nullable Object> Predicate<T> alwaysTrue() {