def test_add_flash_animation(qtbot):
widget = QMainWindow()
qtbot.addWidget(widget)
assert widget.graphicsEffect() is None
add_flash_animation(widget)
assert widget.graphicsEffect() is not None
assert hasattr(widget, "_flash_animation")
qtbot.wait(350)
assert widget.graphicsEffect() is None
assert not hasattr(widget, "_flash_animation")
