message: Made the const reference to the variable
  Created a const reference
diff: @@ -251,7 +251,7 @@ class OpSetsTest : public ExportTest {
  params_.enable_select_tf_ops = false;
  params_.quantize_weights = false;
  - for (OpSet i : sets) {
  + for (const OpSet& i : sets) {
  switch (i) {
  case kTfLiteBuiltins:
  import_all_ops_as_unsupported_ = false;
  