* maximumSize}, {@link #maximumWeight(long) maximumWeight}, {@link #expireAfterWrite
 * expireAfterWrite}, {@link #expireAfterAccess expireAfterAccess}, {@link #weakKeys weakKeys},
 * {@link #weakValues weakValues}, or {@link #softValues softValues} are requested.
 *
 * <p>If {@link #maximumSize(long) maximumSize} or {@link #maximumWeight(long) maximumWeight} is

        return new ConcurrentSkipListMap<>();
    }

    /**
     * {@link ConcurrentSkipListMap}の新しいインスタンスを作成して返します。
     *
     * @param <K>
     *            {@link ConcurrentSkipListMap}のキーの型
     * @param <V>
     *            {@link ConcurrentSkipListMap}の値の型
     * @param c
     *            {@link Comparator}
     * @return {@link ConcurrentSkipListMap}の新しいインスタンス

 * similar to those in this class for non-precondition checks.
 *
 * <h3>{@code java.util.Objects.requireNonNull()}</h3>
 *
 * <p>Projects which use {@code com.google.common} should generally avoid the use of {@link
 * java.util.Objects#requireNonNull(Object)}. Instead, use whichever of {@link

 * basic text processing based on UnicodeSet use the ICU4J UnicodeSetSpanner.
 *
 * <p>Example usages:
 *
 * <pre>
 *   String trimmed = {@link #whitespace() whitespace()}.{@link #trimFrom trimFrom}(userInput);
 *   if ({@link #ascii() ascii()}.{@link #matchesAllOf matchesAllOf}(s)) { ... }</pre>
 *
 * <p>See the Guava User Guide article on <a

   *
   * <ul>
   *   <li>Any {@link ExecutionException} has its <i>cause</i> wrapped in an {@code X} if the cause
   *       is a checked exception, an {@link UncheckedExecutionException} if the cause is a {@code
   *       RuntimeException}, or an {@link ExecutionError} if the cause is an {@code Error}.
   *   <li>Any {@link InterruptedException} is wrapped in an {@code X} (after restoring the

   * #synchronizedMultimap}.
   *
   * <p>Call this method only when the simpler methods {@link ArrayListMultimap#create()}, {@link
   * HashMultimap#create()}, {@link LinkedHashMultimap#create()}, {@link
   * LinkedListMultimap#create()}, {@link TreeMultimap#create()}, and {@link
   * TreeMultimap#create(Comparator, Comparator)} won't suffice.
   *

 * similar to those in this class for non-precondition checks.
 *
 * <h3>{@code java.util.Objects.requireNonNull()}</h3>
 *
 * <p>Projects which use {@code com.google.common} should generally avoid the use of {@link
 * java.util.Objects#requireNonNull(Object)}. Instead, use whichever of {@link

* <a href="https://hub.docker.com/_/mysql" class="external-link" target="_blank">MySQL</a>
* <a href="https://hub.docker.com/_/mongo" class="external-link" target="_blank">MongoDB</a>
* <a href="https://hub.docker.com/_/redis" class="external-link" target="_blank">Redis</a>

и т.п.

/**
 * An abstract implementation of {@link ListenableFuture}, intended for advanced users only. More
 * common ways to create a {@code ListenableFuture} include instantiating a {@link SettableFuture},
 * submitting a task to a {@link ListeningExecutorService}, and deriving a {@code Future} from an
 * existing one, typically using methods like {@link Futures#transform(ListenableFuture,

  /**
   * Returns the empty iterator.
   *
   * <p>The {@link Iterable} equivalent of this method is {@link ImmutableSet#of()}.
   */
  static <T extends @Nullable Object> UnmodifiableIterator<T> emptyIterator() {
    return emptyListIterator();
  }

  /**
   * Returns the empty iterator.
   *
   * <p>The {@link Iterable} equivalent of this method is {@link ImmutableSet#of()}.
   */