code: def _add_trace_frame(self, graph: TraceGraph, trace_frame: TraceFrame) -> None:
          
          trace_frame_id = trace_frame.id.local_id
          self.add_trace_frame(trace_frame)
          self._populate_shared_text(graph, trace_frame.filename_id)
          self._populate_shared_text(graph, trace_frame.caller_id)
          self._populate_shared_text(graph, trace_frame.callee_id)
          for (leaf_id, depth) in graph._trace_frame_leaf_assoc[trace_frame_id]:
              leaf = graph._shared_texts[leaf_id]
              if leaf_id not in self._shared_texts:
                  self.add_shared_text(leaf)
              self.add_trace_frame_leaf_assoc(trace_frame, leaf, depth)
docs: Copies the trace frame from 'graph' to this (self) graph.
          Also copies all the trace_frame-leaf assocs since we don't
          know which ones are needed until we know the issue that reaches it