/**
  * Returns the list of worksheets inside the archive
  *
  * The keys of the array should be the titles of the worksheets
  * The values of the array are the names of the XML worksheet files inside the archive
  *
  * @param Relationships $relationships
  * @param string        $path
  * 
  * @return array
  */
 public function getWorksheetPaths(Relationships $relationships, $path)
 {
     $xml = new \XMLReader();
     $xml->open($path);
     $paths = [];
     while ($xml->read()) {
         if (\XMLReader::ELEMENT === $xml->nodeType && 'sheet' === $xml->name) {
             $rId = $xml->getAttributeNs('id', 'http://schemas.openxmlformats.org/officeDocument/2006/relationships');
             $paths[$xml->getAttribute('name')] = $relationships->getWorksheetPath($rId);
         }
     }
     return $paths;
 }