* #transform} methods all return {@link Double#NaN}. The {@link #inverse} method returns the same
   * instance.
   */
  public static LinearTransformation forNaN() {
    return NaNLinearTransformation.INSTANCE;
  }

  /** Returns whether this is a vertical transformation. */
  public abstract boolean isVertical();

     * @param format the date format pattern or "pdf_date" for PDF date format
     * @return parsed Date object, or null if parsing fails
     */
    public static Date parseDate(final String value, final String format) {
        if (value == null) {
            return null;
        }

        try {
            if (PDF_DATE.equals(format)) {
                final Calendar cal = DateConverter.toCalendar(value);

    assertNull(function.apply("Null"));

    new EqualsTester()
        .addEqualityGroup(function, Functions.forMap(map, 42))
        .addEqualityGroup(Functions.forMap(map))
        .addEqualityGroup(Functions.forMap(map, null))
        .addEqualityGroup(Functions.forMap(map, 43))
        .testEquals();
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester

    assertNull(function.apply("Null"));

    new EqualsTester()
        .addEqualityGroup(function, Functions.forMap(map, 42))
        .addEqualityGroup(Functions.forMap(map))
        .addEqualityGroup(Functions.forMap(map, null))
        .addEqualityGroup(Functions.forMap(map, 43))
        .testEquals();
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester

          thread.setUncaughtExceptionHandler(uncaughtExceptionHandler);
        }
        return thread;
      }
    };
  }

  private static String format(String format, Object... args) {
    return String.format(Locale.ROOT, format, args);
  }

  }

  /**
   * Returns a new {@code TypeResolver} with type variables in {@code formal} mapping to types in
   * {@code actual}.
   *
   * <p>For example, if {@code formal} is a {@code TypeVariable T}, and {@code actual} is {@code
   * String.class}, then {@code new TypeResolver().where(formal, actual)} will {@linkplain
   * #resolveType resolve} {@code ParameterizedType List<T>} to {@code List<String>}, and resolve

        // Setup mock request manager with invalid format
        RequestManager mockRequestManager = createMockRequestManager("invalid_locale_format");

        // Execute
        OptionalThing<Locale> result = provider.findBusinessLocale(null, mockRequestManager);

        // Verify - invalid format should return empty due to exception in LocaleUtils.toLocale
        assertFalse(result.isPresent());

  /**
   * UTF-8: eight-bit UCS Transformation Format.
   *
   * @deprecated Use {@link StandardCharsets#UTF_8} instead.
   */
  @Deprecated public static final Charset UTF_8 = StandardCharsets.UTF_8;

  /**
   * UTF-16BE: sixteen-bit UCS Transformation Format, big-endian byte order.
   *
   * @deprecated Use {@link StandardCharsets#UTF_16BE} instead.
   */

    verify(true, "%s", IGNORE_ME);
  }

  public void testVerify_complexMessage_failure() {
    VerifyException expected = assertThrows(VerifyException.class, () -> verify(false, FORMAT, 5));
    checkMessage(expected);
  }

  private static final String NON_NULL_STRING = "foo";

  public void testVerifyNotNull_simple_success() {
    String result = verifyNotNull(NON_NULL_STRING);

        // Verify the string format
        assertNotNull(result);
        assertTrue(result.contains("FessUserTimeZoneProcessProvider"));
        assertTrue(result.contains("useTimeZoneHandling=false"));
        assertTrue(result.contains("acceptCookieTimeZone=false"));
        assertTrue(result.contains("@"));

        // Verify that hashCode is included in hex format