public function testIsTokenExpired()
 {
     //no token is set so it should return true
     $this->assertTrue($this->ifs->isTokenExpired());
     //token is set and still not expired
     $token = new Token(array('access_token' => '', 'refresh_token' => '', 'expires_in' => 5));
     $this->ifs->setToken($token);
     $this->assertFalse($this->ifs->isTokenExpired());
     //token is set but expired
     $token = new Token(array('access_token' => '', 'refresh_token' => '', 'expires_in' => -5));
     $this->ifs->setToken($token);
     $this->assertTrue($this->ifs->isTokenExpired());
 }