public function testSignsUserOut()
 {
     $userId = 'ddddd';
     $sessionToken = 'sssss';
     $request = new SignOutRequest($userId, $sessionToken);
     $this->server->SetRequest($request);
     $this->authentication->expects($this->once())->method('Logout')->with($this->equalTo($userId), $this->equalTo($sessionToken));
     $this->service->SignOut($this->server);
 }