what if twa_graph_ptr is nullptr?
None of the algorithm in Spot currently contains protection against nullptr automata. That makes it easy to crash a Python kernel, for instance with
>>> import spot
>>> pp = spot.postprocessor()
>>> pp.run(None)
segmentation fault python3
What should we do about that? Do we introduce some common ensure_not_nullptr(aut);
at the beginning of every algorithm, or do we somehow teach Swig about this, keeping the extra checks only in the Python bindings?