public function testStackCalls()
{
$methodCall1 = new DummyMethodCall('mc1');
$methodCall2 = new DummyMethodCall('mc1');
$bag1 = (new MethodCallBag())->with($methodCall1);
$bag2 = $bag1->with($methodCall2);
$this->assertSame([$methodCall1], $this->propRefl->getValue($bag1));
$this->assertSame([$methodCall1, $methodCall2], $this->propRefl->getValue($bag2));
}