def METHOD_NAME(self, load_callback, legal_callback):
    callback = load_callback
    callback.using(legal_callback, 3, 4.0, "5", k=1, l_var="2", j=3.0)
    assert callback._callback_cls == legal_callback
    assert callback._args == (3, 4.0, "5")
    assert callback._kwargs == {"k": 1, "l_var": "2", "j": 3.0}