code: def _sanitize_parameters(self):
          
  
          # Check additional_edges
          if isinstance(self._additional_edges, (list, set, tuple)):
              new_dict = defaultdict(list)
              for s, d in self._additional_edges:
                  new_dict[s].append(d)
              self._additional_edges = new_dict
  
          elif isinstance(self._additional_edges, dict):
              pass
  
          else:
              raise AngrCFGError('Additional edges can only be a list, set, tuple, or a dict.')
  
          # Check _advanced_backward_slicing
          if self._advanced_backward_slicing and self._enable_symbolic_back_traversal:
              raise AngrCFGError('Advanced backward slicing and symbolic back traversal cannot both be enabled.')
  
          if self._advanced_backward_slicing and not self._keep_state:
              raise AngrCFGError('Keep state must be enabled if advanced backward slicing is enabled.')
  
          # Sanitize avoid_runs
          self._avoid_runs = [ ] if self._avoid_runs is None else self._avoid_runs
          if not isinstance(self._avoid_runs, (list, set)):
              raise AngrCFGError('"avoid_runs" must either be None, or a list or a set.')
  
          self._sanitize_starts()
docs: Perform a sanity check on parameters passed in to CFG.__init__().
          An AngrCFGError is raised if any parameter fails the sanity check.
  
          :return: None