message: bug fix: evaluate nodes before swap the original graph
diff: @@ -1922,6 +1922,8 @@ TEST_F(ConstantFoldingTest, PartialFolding_Concat) {
  item.fetch = {"concat0", "concat1", "concat2", "concat3", "concat4",
  "concat5", "concat6", "concat7", "concat8", "concat9"};
  + auto tensors_expected = EvaluateNodes(item.graph, {"concat0"});
  + EXPECT_EQ(1, tensors_expected.size());
  ConstantFolding optimizer(nullptr /* cpu_device */);
  GraphDef output;
  Status status = optimizer.Optimize(nullptr, item, &output);
  @@ -1971,9 +1973,7 @@ TEST_F(ConstantFoldingTest, PartialFolding_Concat) {
  }
  }
  - auto tensors_expected = EvaluateNodes(item.graph, {"concat0"});
  auto tensors = EvaluateNodes(output, {"concat0"});
  - EXPECT_EQ(1, tensors_expected.size());
  EXPECT_EQ(1, tensors.size());
  test::ExpectTensorNear<float>(tensors_expected[0], tensors[0], 1e-6);
  }
  