def _sanitize_parameters(self):
        """
        Perform a sanity check on parameters passed in to CFG.__init__().
        An AngrCFGError is raised if any parameter fails the sanity check.

        :return: None
        """

        # 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()
Perform a sanity check on parameters passed in to CFG.__init__().
        An AngrCFGError is raised if any parameter fails the sanity check.

        :return: None