* Double#NEGATIVE_INFINITY}, or {@link Double#NaN}) then the result is {@link Double#NaN}.
   *
   * @throws IllegalStateException if the dataset is empty
   */
  public double populationCovariance() {
    checkState(count() != 0);
    return sumOfProductsOfDeltas / count();
  }

  /**

     *
     * @param request the HTTP servlet request
     */
    public void deleteUserCodeFromCookie(final HttpServletRequest request) {
        final String cookieValue = getUserCodeFromCookie(request);
        if (cookieValue != null) {
            updateCookie(StringUtil.EMPTY, 0);
        }
    }

    /**

        // Should handle null session ID gracefully
        assertNotNull(urlFilter);
    }

    /**
     * Test initialization with empty session ID
     */
    public void test_init_withEmptySessionId() {
        urlFilter.init("");
        // Should handle empty session ID gracefully
        assertNotNull(urlFilter);
    }

    /**
     * Test adding a single include pattern
     */

    private static String getValue(final List<String> list, final int index) {
        if (index >= list.size()) {
            return StringUtil.EMPTY;
        }
        String item = list.get(index).trim();
        if (StringUtil.isBlank(item)) {
            return StringUtil.EMPTY;
        }
        if (item.length() > 1 && item.charAt(0) == '"' && item.charAt(item.length() - 1) == '"') {

    @Override
    public synchronized void delete(final StemmerOverrideItem item) {
        final StemmerOverrideItem stemmerOverrideItem = item;
        stemmerOverrideItem.setNewInput(StringUtil.EMPTY);
        stemmerOverrideItem.setNewOutput(StringUtil.EMPTY);
        try (StemmerOverrideUpdater updater = new StemmerOverrideUpdater(item)) {
            reload(updater);
        }
    }

    /**

	ID       int               `json:"id"`       // Pool index (zero-based)
	Status   string            `json:"status"`   // Active if rebalance is running, empty otherwise
	Used     float64           `json:"used"`     // Percentage used space
	Progress rebalPoolProgress `json:"progress"` // is empty when rebalance is not running
}

// rebalanceAdminStatus holds rebalance status related information exported to mc, console, etc.

        verify(cfg, times(1)).getBufferCacheSize();
        verify(cfg, times(1)).getMaximumBufferSize();
        verifyNoMoreInteractions(cfg);

        // When cache is empty, getBuffer allocates a new buffer with configured size
        byte[] buf = impl.getBuffer();
        assertNotNull(buf, "getBuffer should never return null");

     * @return the string with highlight tags removed
     */
    protected String removeHighlightTag(final String str) {
        return str.replaceAll(originalHighlightTagPre, StringUtil.EMPTY).replaceAll(originalHighlightTagPost, StringUtil.EMPTY);
    }

    /**
     * Creates highlight information based on screen width.
     * Adjusts fragment size for mobile devices.
     *
     * @return the highlight information

     * existing values in the execution request that are controlled by the toolchains. Hence, it is expected that this
     * method is called on a new/empty execution request before the caller mutates it to fit its needs.
     *
     * @param request The execution request to populate, must not be {@code null}.

)

// ReaderArgs - represents elements inside <InputSerialization><JSON/> in request XML.
type ReaderArgs struct {
	ContentType string `xml:"Type"`
	unmarshaled bool
}

// IsEmpty - returns whether reader args is empty or not.
func (args *ReaderArgs) IsEmpty() bool {
	return !args.unmarshaled
}

// UnmarshalXML - decodes XML data.
func (args *ReaderArgs) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {