code: protected function check(array $files, $path, $source, $template)
      {
          $file = null;
  
          foreach ((array) $files as $key => $value) {
              $filepath = (string) str_replace($path, $source, $value);
  
              $filepath = str_replace('\\', '/', (string) $filepath);
  
              $filepath = (string) preg_replace('/^\d\//i', '', $filepath);
  
              $exists = (string) $filepath === $template;
  
              $lowercase = strtolower($filepath) === $template;
  
              ($exists || $lowercase) && $file = $value;
          }
  
          return $file;
      }
docs: Checks if the specified file exists.
  
  @param  array          $files
  @param  string         $path
  @param  string|integer $source
  @param  string         $template
  @return string|null