message: Add comments about why there should be a dummy op
diff: @@ -295,8 +295,13 @@ class ConstRHSBatchMatMulOpModel : public MultiOpModel {
  CreateBatchMatMulOptions(builder_, adj_x, adj_y).Union(),
  matmul_inputs, matmul_outputs);
  - // This is just a dummy op to check if the values of transposed RHS are
  - // polluted.
  + // Without following ops (not limited to neg), temporary allocation with
  + // kTfLiteArenaRw tends to re-claim the same memory across each evaluation,
  + // and no other ops will modify values at that memory address because no
  + // other memory allocations take place. Therefore, it's likely that results
  + // are correct even if constant transposed RHS is allocated with
  + // kTfLiteArenaRw. We thus use a dummy op to make sure constant transposed
  + // RHS behaves correctly.
  neg_output_id_ = AddOutput(lhs.type);
  std::vector<int> neg_inputs{matmul_output_id_};
  std::vector<int> neg_outputs{neg_output_id_};
  