message: Error checking in c/python code.
diff: @@ -243,6 +243,9 @@ bool GetNextValuesForIterable(PyObject* nested,
  std::vector<Safe_PyObjectPtr>* next_values) {
  PyObject* item;
  PyObject* iterator = PyObject_GetIter(nested);
  + if (iterator == nullptr || PyErr_Occurred()) {
  + return false;
  + }
  while ((item = PyIter_Next(iterator)) != nullptr) {
  next_values->emplace_back(item);
  }
  