code: private function getSiblingContinuousSingleLineComment(Tokens $tokens, $index, $after)
      {
          $siblingIndex = $index;
          do {
              if ($after) {
                  $siblingIndex = $tokens->getNextTokenOfKind($siblingIndex, [[T_COMMENT]]);
              } else {
                  $siblingIndex = $tokens->getPrevTokenOfKind($siblingIndex, [[T_COMMENT]]);
              }
  
              if (null === $siblingIndex) {
                  return null;
              }
          } while (0 === strpos($tokens[$siblingIndex]->getContent(), '/*'));
  
          $newLines = 0;
          for ($i = min($siblingIndex, $index) + 1, $max = max($siblingIndex, $index); $i < $max; ++$i) {
              if ($tokens[$i]->isWhitespace() && Preg::match('/\R/', $tokens[$i]->getContent())) {
                  if (1 === $newLines || Preg::match('/\R.*\R/', $tokens[$i]->getContent())) {
                      return null;
                  }
  
                  ++$newLines;
              }
          }
  
          return $siblingIndex;
      }
docs: @param Tokens $tokens
  @param int    $index
  @param bool   $after
  
  @return null|int