message: now all the utest can run with PASS
diff: "snapshot": 10000,
  "snapshot_prefix": "./",
  "eval_interval": 1000,
  - "eval_batches": 100,
  - "dense_model_file": "./criteo.model",
  - "sparse_model_file": ["./Sparse1.model", "./Sparse2.model"]
  + "eval_batches": 100
  },
  "optimizer": {
  "bottom": "data1",
  "top": "sparse_embedding1",
  "sparse_embedding_hparam": {
  - "vocabulary_size": 1603616,
  + "vocabulary_size": 2603616,
  "load_factor": 0.75,
  "embedding_vec_size": 64,
  "combiner": 1
  "bottom": "data2",
  "top": "sparse_embedding2",
  "sparse_embedding_hparam": {
  - "vocabulary_size": 1603616,
  + "vocabulary_size": 2603616,
  "load_factor": 0.75,
  "embedding_vec_size": 64,
  "combiner": 1
  