code: public function setUser(UserInterface $user)
      {
          if ($this->user) {
              $this->getPermissions()->revoke($this->user, Permissions::PERMISSION_ALL, false);
          }
          $this->user = $user;
          $this->getPermissions()->grant($user, Permissions::PERMISSION_ALL);
          
          return $this;
      }
docs: Sets the owner of a file
  
  @param UserInterface $user
  @return $this