code: def _pre_process_cfg(self):
          
          for _, dst, data in self._acyclic_cfg.graph.edges(data=True):
              if 'jumpkind' in data and data['jumpkind'] == 'Ijk_FakeRet':
                  all_edges_to_dst = self._acyclic_cfg.graph.in_edges([ dst ], data=True)
                  if not any((s, d) for s, d, da in all_edges_to_dst if da['jumpkind'] != 'Ijk_FakeRet' ):
                      # All in edges are FakeRets
                      # Change them to a normal edge
                      for _, _, data_ in all_edges_to_dst:
                          data_['jumpkind'] = 'Ijk_Boring'
docs: Pre-process the acyclic CFG.
          - Change all FakeRet edges to normal edges when necessary (e.g. the normal/expected return edge does not exist)