public function testCanCumulateExtendFlags()
{
$extendFlag1 = new ExtendFlag(new FixtureReference('user_base'));
$extendFlag2 = new ExtendFlag(new FixtureReference('user_with_owner'));
$flags = (new FlagBag('user0'))->withFlag($extendFlag1)->withFlag($extendFlag2);
$this->assertSameFlags([$extendFlag1, $extendFlag2], $flags);
}