* than {@code size()}. Furthermore, this structure only depends on a fixed number of arrays; {@code
 * add(x)} operations <i>do not</i> create objects for the garbage collector to deal with, and for
 * every element added, the garbage collector will have to traverse {@code 1.5} references on
 * average, in the marking phase, not {@code 5.0} as in {@code java.util.HashSet}.
 *

   */
  public static <T extends @Nullable Object> Predicate<T> in(Collection<? extends T> target) {
    return new InPredicate<>(target);
  }

  /**
   * Returns the composition of a function and a predicate. For every {@code x}, the generated
   * predicate returns {@code predicate(function(x))}.
   *
   * @return the composition of the provided function and predicate
   */

 * environment if possible) before spending a lot of effort on tweaking a particular element.
 *
 * <h3>Other types of preconditions</h3>
 *
 * <p>Not every type of precondition failure is supported by these methods. Continue to throw
 * standard JDK exceptions such as {@link java.util.NoSuchElementException} or {@link
 * UnsupportedOperationException} in the situations they are intended for.

   * map.
   *
   * <p>The returned map isn't threadsafe or serializable, even if {@code unfiltered} is.
   *
   * <p>Many of the filtered map's methods, such as {@code size()}, iterate across every key/value
   * mapping in the underlying map and determine which satisfy the filter. When a live view is
   * <i>not</i> needed, it may be faster to copy the filtered map and use the copy.
   *

   * the underlying collection.
   *
   * <p>The returned collection isn't threadsafe or serializable, even if {@code unfiltered} is.
   *
   * <p>Many of the filtered collection's methods, such as {@code size()}, iterate across every
   * element in the underlying collection and determine which elements satisfy the filter. When a
   * live view is <i>not</i> needed, it may be faster to copy {@code Iterables.filter(unfiltered,
   * predicate)} and use the copy.

   *       Executor)} instead, with a function that returns the next value directly.
   *   <li>Call {@link DeferredCloser#eventuallyClose(Object, Executor) closer.eventuallyClose()}
   *       for every closeable object this step creates in order to capture it for later closing.
   *   <li>Return a {@code ClosingFuture}. To turn a {@link ListenableFuture} into a {@code
   *       ClosingFuture} call {@link #from(ListenableFuture)}.

  private void assertEntrySetNotContainsString(Set<Entry<K, V>> entrySet) {
    // Very unlikely that a buggy collection would ever return true. It might accidentally throw.
    assertFalse(entrySet.contains("foo"));
  }

  /**
   * Override this to check invariants which should hold true for a particular implementation, but
   * which are not generally applicable to every instance of Map.
   *

    Integer javaVersion = Ints.tryParse(JAVA_SPECIFICATION_VERSION.value());
    if (javaVersion != null && javaVersion >= 9) {
      return;
    }
    // Obviously this isn't guaranteed in every environment, but it works well enough for now:
    assertTrue(lazyStackTraceIsLazy());
  }

  @J2ktIncompatible
  @GwtIncompatible // lazyStackTrace(Throwable)
  public void testLazyStackTrace() {

    Integer javaVersion = Ints.tryParse(JAVA_SPECIFICATION_VERSION.value());
    if (javaVersion != null && javaVersion >= 9) {
      return;
    }
    // Obviously this isn't guaranteed in every environment, but it works well enough for now:
    assertTrue(lazyStackTraceIsLazy());
  }

  @J2ktIncompatible
  @GwtIncompatible // lazyStackTrace(Throwable)
  public void testLazyStackTrace() {

  }

  /**
   * Notifies listeners that an entry has been automatically removed due to expiration, eviction, or
   * eligibility for garbage collection. This should be called every time expireEntries or
   * evictEntry is called (once the lock is released).
   */
  void processPendingNotifications() {
    RemovalNotification<K, V> notification;