code: private function getLineBreakCount(Tokens $tokens, $whiteSpaceStartIndex, $whiteSpaceEndIndex)
      {
          $lineCount = 0;
          for ($i = $whiteSpaceStartIndex; $i < $whiteSpaceEndIndex; ++$i) {
              $lineCount += substr_count($tokens[$i]->getContent(), "\n");
          }
  
          return $lineCount;
      }
docs: @param Tokens $tokens
  @param int    $whiteSpaceStartIndex
  @param int    $whiteSpaceEndIndex
  
  @return int