* #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();

   *
   * <p>If the dataset contains any non-finite values ({@link Double#POSITIVE_INFINITY}, {@link
   * Double#NEGATIVE_INFINITY}, or {@link Double#NaN}) then the result is {@link
   * LinearTransformation#forNaN()}.
   *
   * @throws IllegalStateException if the dataset is empty or contains a single pair of values, or
   *     both the {@code x} and {@code y} dataset must have zero population variance
   */

        SEARCH,
        /** Label API format. */
        LABEL,
        /** Popular word API format. */
        POPULARWORD,
        /** Favorite API format. */
        FAVORITE,
        /** Favorites API format. */
        FAVORITES,
        /** Ping API format. */
        PING,
        /** Scroll API format. */
        SCROLL,
        /** Suggest API format. */
        SUGGEST,
        /** Other API format. */

     * @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

 * <td>{@link DateFormat#SHORT} format</td>
 * <td>{@literal yy/MM/dd}</td>
 * </tr>
 * <tr>
 * <td>{@link DateFormat#MEDIUM} format</td>
 * <td>{@literal yyyy/MM/dd}</td>
 * </tr>
 * <tr>
 * <td>{@link DateFormat#LONG} format</td>
 * <td>{@literal yyyy/MM/dd}</td>
 * </tr>
 * <tr>
 * <td>{@link DateFormat#FULL} format</td>
 * <td>{@literal yyyy'nen'M'gatsu'd'nichi'}</td>
 * </tr>

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

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

        final Date date = toDate("11:49");
        assertThat(new SimpleDateFormat("HH:mm:ss").format(date), is("11:49:00"));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testToDate_MediumStyle() throws Exception {
        final Date date = toDate("11:49:10");
        assertThat(new SimpleDateFormat("HH:mm:ss").format(date), is("11:49:10"));
    }

    /**
     * @throws Exception
     */

  public void testNameFormatWithPercentS_custom() {
    String format = "super-duper-thread-%s";
    ThreadFactory factory = builder.setNameFormat(format).build();
    for (int i = 0; i < 11; i++) {
      assertEquals(rootLocaleFormat(format, i), factory.newThread(monitoredRunnable).getName());
    }
  }

  public void testNameFormatWithPercentD_custom() {
    String format = "super-duper-thread-%d";