def METHOD_NAME(self) -> None:
    """Regression test for #2243."""
    # Arrange
    event1 = Event(
        slug="2022-01-01-test", start=date(2022, 1, 1), end=date(2022, 1, 2)
    )
    event2 = Event(slug="2022-02-01-test", start=None, end=date(2022, 2, 2))
    event3 = Event(slug="2022-03-01-test", start=date(2022, 3, 1), end=None)
    event4 = Event(slug="2022-xx-xx-test", start=None, end=None)
    events = [event1, event2, event3, event4]
    event = Event(
        slug="2022-01-02-test", start=date(2022, 1, 2), end=date(2022, 1, 3)
    )
    # Act
    results = get_event_conflicts(events, event)
    # Assert
    self.assertEqual(results, [event1])