code: private function findHeaderCommentCurrentIndex(Tokens $tokens, $headerNewIndex)
      {
          $index = $tokens->getNextNonWhitespace($headerNewIndex);
  
          return null === $index || !$tokens[$index]->isComment() ? null : $index;
      }
docs: @param Tokens $tokens
  @param int    $headerNewIndex
  
  @return null|int