def __init__()

in sapp/trace_graph.py [0:0]


    def __init__(self) -> None:
        self._issues: Dict[int, Issue] = {}
        self._issue_instances: Dict[int, IssueInstance] = {}
        self._trace_annotations: Dict[int, TraceFrameAnnotation] = {}

        # Create a mapping of (caller_id, caller_port) to the corresponding
        # trace frame's id.
        self._trace_frames_map: DefaultDict[
            TraceKind, DefaultDict[Tuple[int, str], Set[int]]
        ] = defaultdict(lambda: defaultdict(set))

        # Similar to _trace_frames_map, but maps the reverse direction
        # of the trace graph, i.e. (callee_id, callee_port) to the
        # trace_frame_id.
        self._trace_frames_rev_map: DefaultDict[
            TraceKind, DefaultDict[Tuple[int, str], Set[int]]
        ] = defaultdict(lambda: defaultdict(set))

        self._trace_frames: Dict[int, TraceFrame] = {}

        self._features: Dict[int, Feature] = {}

        self._feature_lookup: Dict[str, int] = {}

        self._shared_texts: Dict[int, SharedText] = {}
        self._shared_text_lookup: (
            DefaultDict[SharedTextKind, Dict[str, int]]
        ) = defaultdict(dict)

        self._trace_frame_leaf_assoc: DefaultDict[int, LeafIDToDepthMap] = defaultdict(
            lambda: {}
        )

        self._trace_frame_issue_instance_assoc: DefaultDict[
            int, Set[int]
        ] = defaultdict(set)
        self._issue_instance_trace_frame_assoc: DefaultDict[
            int, Set[int]
        ] = defaultdict(set)

        self._trace_frame_annotation_trace_frame_assoc: DefaultDict[
            int, Set[int]
        ] = defaultdict(set)
        self._trace_frame_trace_frame_annotation_assoc: DefaultDict[
            int, Set[int]
        ] = defaultdict(set)

        self._issue_instance_shared_text_assoc: DefaultDict[
            int, Set[int]
        ] = defaultdict(set)
        self._shared_text_issue_instance_assoc: DefaultDict[
            int, Set[int]
        ] = defaultdict(set)

        self._issue_instance_feature_assoc: DefaultDict[int, Set[int]] = defaultdict(
            set
        )
        self._feature_issue_instance_assoc: DefaultDict[int, Set[int]] = defaultdict(
            set
        )

        self._issue_instance_fix_info: Dict[int, IssueInstanceFixInfo] = {}