code: private static int firstNonMatchPosition(Slice utf8, int[] codePointsToMatch)
      {
          int length = utf8.length();
  
          int position = 0;
          while (position < length) {
              int codePoint = tryGetCodePointAt(utf8, position);
              if (codePoint < 0) {
                  break;
              }
              if (!matches(codePoint, codePointsToMatch)) {
                  break;
              }
              position += lengthOfCodePoint(codePoint);
          }
          return position;
      }
docs: This function is an exact duplicate of firstNonWhitespacePosition(Slice) except for one line.