[This line](https://code.kodo.org.uk/dom/behave-utils/-/blob/c3e8651fe29cd5ed86915f508522c93a0ee0c3e9/behave_utils/proc.py#L331) should raise a `TypeError`, not an `AssertionError`: ```python # TODO: Can the nested `if` code be flattened without confusing the optimiser in Python 3.9? if not TYPE_CHECKING: if deserialiser and query: raise TypeError(...) ```