void test_T2s(Tensor1< double, 3 > &t1_1, const Tensor1< double, 3 > &t1_2, Tensor2< double, 3, 3 > &t2_1, const Tensor2< double, 3, 3 > &t2_2, Tensor2_symmetric< double, 3 > &t2s_1, const Tensor2_symmetric< double, 3 > &t2s_2, const Tensor2_symmetric< double, 3 > &t2s_3)