code: ///////////////////////////////////////////////////////////////////////////////////////////////
  // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
  // Copyright (C) 2001-2023 the original author or authors.
  //
  // This library is free software; you can redistribute it and/or
  // modify it under the terms of the GNU Lesser General Public
  // License as published by the Free Software Foundation; either
  // version 2.1 of the License, or (at your option) any later version.
  //
  // This library is distributed in the hope that it will be useful,
  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  // Lesser General Public License for more details.
  //
  // You should have received a copy of the GNU Lesser General Public
  // License along with this library; if not, write to the Free Software
  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  ///////////////////////////////////////////////////////////////////////////////////////////////
  
  package com.puppycrawl.tools.checkstyle.utils;
  
  import java.util.Arrays;
  
  /**
   * Contains utility methods for code point.
   */
  public final class CodePointUtil {
  
      /** Stop instances being created. **/
      private CodePointUtil() {
      }
  
      /**
       * Checks if given code point array is blank by either being empty,
       * or contains only whitespace characters.
       *
       * @param codePoints The array of unicode code points of string to check.
       * @return true if codePoints is blank.
       */
      public static boolean isBlank(int... codePoints) {
          return hasWhitespaceBefore(codePoints.length, codePoints);
      }
  
      /**
       * Checks if the given code point array contains only whitespace up to specified index.
       *
       * @param codePoints
       *            array of Unicode code point of string to check
       * @param index
       *            index to check up to (exclusive)
       * @return true if all code points preceding given index are whitespace
       */
      public static boolean hasWhitespaceBefore(int index, int... codePoints) {
          return Arrays.stream(codePoints, 0, index)
                  .allMatch(Character::isWhitespace);
      }
  
      /**
       * Removes trailing whitespaces.
       *
       * @param codePoints array of unicode code points
       * @return unicode code points array with trailing whitespaces removed
       */
      public static int[] stripTrailing(int... codePoints) {
          int lastIndex = codePoints.length;
          while (lastIndex > 0 && CommonUtil.isCodePointWhitespace(codePoints, lastIndex - 1)) {
              lastIndex--;
          }
          return Arrays.copyOfRange(codePoints, 0, lastIndex);
      }
  
      /**
       * Removes leading whitespaces.
       *
       * @param codePoints array of unicode code points
       * @return unicode code points array with leading whitespaces removed
       */
      public static int[] stripLeading(int... codePoints) {
          int startIndex = 0;
          while (startIndex < codePoints.length
              && CommonUtil.isCodePointWhitespace(codePoints, startIndex)) {
              startIndex++;
          }
          return Arrays.copyOfRange(codePoints, startIndex, codePoints.length);
      }
  
      /**
       * Removes leading and trailing whitespaces.
       *
       * @param codePoints array of unicode code points
       * @return unicode code points array with leading and trailing whitespaces removed
       */
      public static int[] trim(int... codePoints) {
          final int[] strippedCodePoints = stripTrailing(codePoints);
          return stripLeading(strippedCodePoints);
      }
  
      /**
       * Tests if the unicode code points array
       * ends with the specified suffix.
       *
       * @param suffix the suffix
       * @param codePoints the array of unicode code points to check
       * @return {@code true}, if the unicode code points array ends with provided suffix
       */
      public static boolean endsWith(int[] codePoints, String suffix) {
          final int startIndex = codePoints.length - suffix.length();
          return startIndex > -1 && Arrays.equals(Arrays
                      .copyOfRange(codePoints, startIndex, codePoints.length),
                      suffix.codePoints().toArray());
      }
  }
  