/**
  * 
  * @param File $file
  * @return boolean
  */
 public function canSendToBrowser(File $file = null)
 {
     $canViewFront = true;
     if ($file instanceof File) {
         // Implement all file extensions with canViewFront()
         $cans = $file->extend('canViewFront');
         if ($cans && is_array($cans)) {
             foreach ($cans as $can) {
                 $canViewFront = $can && $canViewFront;
             }
         } else {
             $canViewFront = false;
         }
     } else {
         $canViewFront = false;
     }
     return $canViewFront;
 }
 public function canDownloadFile(File $file = null)
 {
     if ($file instanceof File) {
         // Implement a FileExtension with canDownload(), and we'll test that first
         $results = $file->extend('canDownload');
         if ($results && is_array($results)) {
             if (!min($results)) {
                 return false;
             } else {
                 return true;
             }
         }
         // If an extension with canDownload() can't be found, fallback to using canView
         if ($file->canView()) {
             return true;
         }
         return false;
     }
     return false;
 }