code: public function getPermissions()
      {
          if (!$this->permissions) {
              $perms = new Permissions();
              if ($this->user instanceof UserInterface) {
                  $perms->grant($this->user, PermissionsInterface::PERMISSION_ALL);
              }
              $this->setPermissions($perms);
          }
          return $this->permissions;
      }
docs: Gets Permissions of a file
  
  @return PermissionsInterface