code: public function canRead($pFilename)
      {
          File::assertFile($pFilename);
  
          $xl = false;
          // Load file
          $zip = new ZipArchive();
          if ($zip->open($pFilename) === true) {
              // check if it is an OOXML archive
              $rels = simplexml_load_string(
                  $this->securityScan(
                      $this->getFromZipArchive($zip, '_rels/.rels')
                  ),
                  'SimpleXMLElement',
                  Settings::getLibXmlLoaderOptions()
              );
              if ($rels !== false) {
                  foreach ($rels->Relationship as $rel) {
                      switch ($rel['Type']) {
                          case 'http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument':
                              if (basename($rel['Target']) == 'workbook.xml') {
                                  $xl = true;
                              }
  
                              break;
                      }
                  }
              }
              $zip->close();
          }
  
          return $xl;
      }
docs: Can the current IReader read the file?
  
  @param string $pFilename
  
  @throws Exception
  
  @return bool