Method set_test_only

common/expr.h:221–221

  ABSL_MUST_USE_RESULT bool test_only() const { return test_only_; }

  void set_test_only(bool test_only) { test_only_ = test_only; }

  friend void swap(SelectExpr& lhs, SelectExpr& rhs) noexcept {
    using std::swap;