message: Check that axis is a scalar
diff: @@ -1913,6 +1913,10 @@ tensorflow::Status ConvertExpandDims(OpConverterParams* params) {
  const int input_rank = input_dims.size();
  // Get axis to expand on.
  TRT_ShapedWeights weights = inputs.at(1).weights();
  + if (weights.count() != 1) {
  + return tensorflow::errors::InvalidArgument(
  + "ExpandDims axis must be a scalar, at ", node_def.name());
  + }
  const int* weights_ptr =
  static_cast<int*>(const_cast<void*>(weights.GetValues()));
  int axis = weights_ptr[0];
  