message: Skip optional tensors during calibration.
diff: @@ -203,6 +203,9 @@ std::vector<int> GetLoggableTensorIndices(
  const flatbuffers::Vector<flatbuffers::Offset<Buffer>>* tensor_buffers) {
  std::vector<int> loggable;
  for (auto tensor_index : tensor_indices) {
  + if (tensor_index == kOptionalTensor) {
  + continue;
  + }
  auto tensor = tensors->Get(tensor_index);
  auto buffer_index = tensor->buffer();
  const bool has_no_buffer =
  