message: Prevent null pointer dereference in `mutable_graph_view`
diff: @@ -68,6 +68,9 @@ bool IsIdentityConsumingSwitch(const MutableGraphView& graph,
  }
  NodeDef* input_node = graph.GetNode(tensor_id.node());
  + if (input_node == nullptr) {
  + return false;
  + }
  return IsSwitch(*input_node);
  }
  return false;
  