* Returns the index of the first matching BMP character in a character sequence, or {@code -1} if
   * no matching character is present.
   *
   * <p>The default implementation iterates over the sequence in forward order calling {@link
   * #matches} for each character.
   *
   * @param sequence the character sequence to examine from the beginning
   * @return an index, or {@code -1} if no character matches
   */

 *
 * Percent encoding replaces a character (like `\ud83c\udf69`) with its UTF-8 hex bytes (like
 * `%F0%9F%8D%A9`). This approach works for whitespace characters, control characters, non-ASCII
 * characters, and characters that already have another meaning in a particular context.
 *
 * Percent encoding is used in every URL component except for the hostname. But the set of

    // Host names are special:
    //
    //  * Several characters are forbidden and must throw exceptions if used.
    //  * They don't use percent escaping at all.
    //  * They use punycode for internationalization.
    //  * URI is much more strict than HttpUrl or URL on what's accepted.
    //
    // HttpUrl is quite lenient with what characters it accepts. In particular, characters like '{'

     </dependency>
     ```


## Version 3.3.1

_2016-05-28_

 *  Fix: The plaintext check in HttpLoggingInterceptor incorrectly classified
    newline characters as control characters. This is fixed.
 *  Fix: Don't crash reading non-ASCII characters in HTTP/2 headers or in cached
    HTTP headers.
 *  Fix: Retain the response body when an attempt to open a web socket returns a
    non-101 response code.

     */
    public void setEncodeUrlLink(final boolean encodeUrlLink) {
        this.encodeUrlLink = encodeUrlLink;
    }

    /**
     * Sets the character encoding for URL links.
     *
     * @param urlLinkEncoding the character encoding to use
     */
    public void setUrlLinkEncoding(final String urlLinkEncoding) {
        this.urlLinkEncoding = urlLinkEncoding;
    }

    /**

   * encounter order of the streams of values.
   *
   * <p>Example:
   *
   * {@snippet :
   * static final ListMultimap<Character, Character> FIRST_LETTER_MULTIMAP =
   *     Stream.of("banana", "apple", "carrot", "asparagus", "cherry")
   *         .collect(
   *             flatteningToMultimap(
   *                  str -> str.charAt(0),

   * encounter order of the streams of values.
   *
   * <p>Example:
   *
   * {@snippet :
   * static final ListMultimap<Character, Character> FIRST_LETTER_MULTIMAP =
   *     Stream.of("banana", "apple", "carrot", "asparagus", "cherry")
   *         .collect(
   *             flatteningToMultimap(
   *                  str -> str.charAt(0),

crawler.document.duplicate.term.removed=false
# Unicode space characters for document parsing.
crawler.document.space.chars=u0009u000Au000Bu000Cu000Du001Cu001Du001Eu001Fu0020u00A0u1680u180Eu2000u2001u2002u2003u2004u2005u2006u2007u2008u2009u200Au200Bu200Cu202Fu205Fu3000uFEFFuFFFDu00B6
# Unicode full stop characters for document parsing.
crawler.document.fullstop.chars=u002eu06d4u2e3cu3002
# Encoding for crawling data.

            return replaceWithUnderscores(value);
        }
        return value;
    }

    /**
     * Replaces special characters in a string with underscores for group names.
     *
     * @param value the string to process
     * @return the string with special characters replaced by underscores
     */
    protected String replaceWithUnderscores(final String value) {

        String[] spaces = (String[]) propMap.get(CRAWLER_DOCUMENT_SPACES);
        if (spaces == null) {
            spaces = Arrays.stream(getCrawlerDocumentSpaceCharsAsArray()).mapToObj(Character::toString).toArray(n -> new String[n]);
            propMap.put(CRAWLER_DOCUMENT_SPACES, spaces);
        }
        return spaces;
    }