async def test_upcast_event_handler_arg(handler, payload):
    """Test that upcast event handler args work correctly.

    Args:
        handler: The handler to test.
        payload: The payload to test.
    """
    state = UpcastState()
    async for update in state._process_event(handler, state, payload):
        assert update.delta == {UpcastState.get_full_name(): {"passed": True}}
Test that upcast event handler args work correctly.

    Args:
        handler: The handler to test.
        payload: The payload to test.
    
tests/units/test_state.py