}

  // common.base
  @Empty
  <T> com.google.common.base.Optional<T> generateGoogleOptional() {
    return com.google.common.base.Optional.absent();
  }

  @Generates
  <T> com.google.common.base.Optional<T> generateGoogleOptional(T value) {
    return com.google.common.base.Optional.of(value);
  }

  @Generates
  Joiner generateJoiner() {

   *
   * @since 8.0
   */
  public static final byte ESC = 27;

  /**
   * File Separator: These four information separators may be used within data in optional fashion,
   * except that their hierarchical relationship shall be: FS is the most inclusive, then GS, then
   * RS, and US is least inclusive. (The content and length of a File, Group, Record, or Unit are
   * not specified.)

   * Predicates.notNull())}, static importing as necessary.
   *
   * <p><b>Note:</b> if {@code first} is represented as an {@link Optional}, this can be
   * accomplished with {@link Optional#or(Object) first.or(second)}. That approach also allows for
   * lazy evaluation of the fallback instance, using {@link Optional#or(Supplier)
   * first.or(supplier)}.
   *
   * <p><b>Java 9 users:</b> use {@code java.util.Objects.requireNonNullElse(first, second)}

            .addValue(null)
            .add(SHORT_NAME, java.util.Optional.of("1"))
            .add(LONG_NAME, java.util.Optional.of("1"))
            .add(SHORT_NAME, java.util.Optional.empty())
            .add(LONG_NAME, java.util.Optional.empty())
            .add(SHORT_NAME, Optional.of("2"))
            .add(SHORT_NAME, Optional.absent())
            .addValue(null)
            .add(SHORT_NAME, new int[] {1})

    }

    @Override
    public Optional<Long> sizeIfKnown() {
      Optional<Long> optionalUnslicedSize = ByteSource.this.sizeIfKnown();
      if (optionalUnslicedSize.isPresent()) {
        long unslicedSize = optionalUnslicedSize.get();
        long off = Math.min(offset, unslicedSize);
        return Optional.of(Math.min(length, unslicedSize - off));
      }
      return Optional.absent();
    }

    @Override

 * order of the various views.
 *
 * <p>The views returned by {@link #column}, {@link #columnKeySet()}, and {@link #columnMap()} have
 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in

  }

  @AndroidIncompatible
  public void testJavaOptional() {
    FreshValueGenerator generator = new FreshValueGenerator();
    assertEquals(Optional.empty(), generator.generateFresh(new TypeToken<Optional<String>>() {}));
    assertEquals(Optional.of("2"), generator.generateFresh(new TypeToken<Optional<String>>() {}));

   * @return {@code Optional.of(onlyElement)} if the stream has exactly one element (must not be
   *     {@code null}) and returns {@code Optional.empty()} if it has none.
   */
  @SuppressWarnings("unchecked")
  public static <T> Collector<T, ?, Optional<T>> toOptional() {
    return (Collector) TO_OPTIONAL;
  }

  private static final Object NULL_PLACEHOLDER = new Object();

    }

    @Override
    public Optional<Long> lengthIfKnown() {
      long result = 0L;
      for (CharSource source : sources) {
        Optional<Long> lengthIfKnown = source.lengthIfKnown();
        if (!lengthIfKnown.isPresent()) {
          return Optional.absent();
        }
        result += lengthIfKnown.get();
      }
      return Optional.of(result);
    }

    @Override

  /** Puts all the associations from {@code rangeMap} into this range map (optional operation). */
  void putAll(RangeMap<K, ? extends V> rangeMap);

  /** Removes all associations from this range map (optional operation). */
  void clear();

  /**
   * Removes all associations from this range map in the specified range (optional operation).
   *