* #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 have zero population variance
   */

   *
   * <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
   */

    assertThrows(IllegalArgumentException.class, () -> LinearTransformation.horizontal(Double.NaN));
  }

  public void testForNaN() {
    LinearTransformation transformation = LinearTransformation.forNaN();
    assertLinearTransformationNaN(transformation);
  }

    assertThrows(IllegalArgumentException.class, () -> LinearTransformation.horizontal(Double.NaN));
  }

  public void testForNaN() {
    LinearTransformation transformation = LinearTransformation.forNaN();
    assertLinearTransformationNaN(transformation);
  }

  /**
   * Converts the specified {@code String str} from this format to the specified {@code format}. A
   * "best effort" approach is taken; if {@code str} does not conform to the assumed format, then
   * the behavior of this method is undefined but we make a reasonable effort at converting anyway.
   */
  public final String to(CaseFormat format, String str) {
    checkNotNull(format);
    checkNotNull(str);

        final Date date = toDate("10/9/7");
        assertThat(new SimpleDateFormat("yyyy/MM/dd").format(date), is("2010/09/07"));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testToDate_MediumStyle() throws Exception {
        final Date date = toDate("2010/9/7");
        assertThat(new SimpleDateFormat("yyyy/MM/dd").format(date), is("2010/09/07"));
    }

    /**
     * @throws Exception
     */

        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. */

              if (this.timePicker) {
                    var format = this.timePickerSeconds ? "YYYY-MM-DD HH:mm:ss" : "YYYY-MM-DD HH:mm";
                    //ignore times when comparing dates if time picker seconds is not enabled
                    if (this.startDate.format(format) == this.ranges[range][0].format(format) && this.endDate.format(format) == this.ranges[range][1].format(format)) {
                        customRange = false;

     * @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);