`TypeError` in exact signature computation

[Alex Van Mechelen]

Steps to reproduce

exe = Executable("dataset-packed-pe/packed/ASPack/aspack_ntfsinfo.exe")
exe.cfg.acyclic_graph.signature(128, True)

Traceback

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/user/.local/lib/python3.11/site-packages/pbox/core/executable/cfg/graph.py", line 153, in signature
    for j, successor in sorted(self.successors(node), key=lambda n: -n.soot_block['depth']):
        ^^^^^^^^^^^^
  File "/home/user/.local/lib/python3.11/site-packages/pbox/helpers/mixins.py", line 18, in __getitem__
    return super(GetItemMixin, self).__getitem__(name)
           ^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: super(type, obj): obj must be an instance or subtype of type