diff --git a/.gitignore b/.gitignore
index c2cc671..4addbea 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,4 +6,5 @@ __pycache__/
 /examples/exp/
 /dist/
 /test/
-/asset/
\ No newline at end of file
+/asset/
+.pytest_cache/
\ No newline at end of file
diff --git a/LICENSE b/LICENSE
index 192c8bd..693ed5d 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2022 ustcml
+Copyright (c) 2022 Jintao
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/README.md b/README.md
index f20a6ff..84b021b 100644
--- a/README.md
+++ b/README.md
@@ -4,8 +4,8 @@
 ## Introduction
 1. [Mini-Lightning](https://github.com/ustcml/mini-lightning/) is a Lightweight machine learning training library, which is a mini version of [Pytorch-Lightning](https://www.pytorchlightning.ai/) with only 1k lines of code. It has the advantages of faster, more concise and more flexible.
 2. Existing features: support for DDP(multi-node and multi-gpu), Sync-BN, DP, AMP, gradient accumulation, warmup and lr_scheduler, grad clip, tensorboard, model and result saving, beautiful console log, torchmetrics, etc.
-3. Only the minimal interfaces are exposed, keeping the features of simplicity, easy to read, use and extend. Additional functions can be found in [ml_alg](https://github.com/Jintao-Huang/ml_alg)
-4. examples can be found in `/examples/`
+3. Only the minimal interfaces are exposed, keeping the features of simplicity, easy to read, use and extend.
+4. examples can be found in `examples/`
 5. If you have any problems or bug finding, please raise issue, Thank you.
 
 
@@ -13,7 +13,7 @@
 1. Download the latest version(>=1.12) of Torch(corresponding CUDA version) from the [official website](https://pytorch.org/get-started/locally/) of Torch. It is not recommended to automatically install Torch (CUDA 10.2) using the Mini-Lightning dependency, which will cause CUDA version mismatch.
 2. Install mini-lightning
 ```bash
-# from pypi (v0.1.0)
+# from pypi (v0.1.1)
 pip install mini-lightning
 
 # Or download the files from the repository to local,
diff --git a/examples/cv.py b/examples/cv.py
index eab8766..6bb9bb8 100644
--- a/examples/cv.py
+++ b/examples/cv.py
@@ -120,7 +120,7 @@ def test_step(self, batch: Any) -> None:
 
     def collect_res(seed: int) -> Dict[str, float]:
         ml.seed_everything(seed, gpu_dtm=False)
-        model = tvm.resnet50(**hparams["model_hparams"])
+        model = getattr(tvm, hparams["model_name"])(**hparams["model_hparams"])
         state_dict = torch.hub.load_state_dict_from_url(**hparams["model_pretrain_model"])
         state_dict = ml._remove_keys(state_dict, ["fc"])
         logger.info(model.load_state_dict(state_dict, strict=False))
diff --git a/examples/cv_ddp.py b/examples/cv_ddp.py
index 4c101a0..0e3792a 100644
--- a/examples/cv_ddp.py
+++ b/examples/cv_ddp.py
@@ -135,7 +135,7 @@ def parse_opt() -> Namespace:
     def collect_res(seed: int) -> Dict[str, float]:
         # Different GPUs use different seeds. Each GPU behaves differently
         ml.seed_everything(seed + rank, gpu_dtm=False)
-        model = tvm.resnet50(**hparams["model_hparams"])
+        model = getattr(tvm, hparams["model_name"])(**hparams["model_hparams"])
         state_dict = torch.hub.load_state_dict_from_url(**hparams["model_pretrain_model"])
         state_dict = ml._remove_keys(state_dict, ["fc"])
         if rank in {-1, 0}:
diff --git a/examples/cv_ddp_spawn.py b/examples/cv_ddp_spawn.py
index bb6f986..fa25d1f 100644
--- a/examples/cv_ddp_spawn.py
+++ b/examples/cv_ddp_spawn.py
@@ -130,7 +130,7 @@ def main(rank: int, world_size: int, device_ids: List[int]) -> None:
     def collect_res(seed: int) -> Dict[str, float]:
         # Different GPUs use different seeds. Each GPU behaves differently
         ml.seed_everything(seed + rank, gpu_dtm=False)
-        model = tvm.resnet50(**hparams["model_hparams"])
+        model = getattr(tvm, hparams["model_name"])(**hparams["model_hparams"])
         state_dict = torch.hub.load_state_dict_from_url(**hparams["model_pretrain_model"])
         state_dict = ml._remove_keys(state_dict, ["fc"])
         if rank in {-1, 0}:
diff --git a/examples/dqn.py b/examples/dqn.py
index cac0c9d..ae9686d 100644
--- a/examples/dqn.py
+++ b/examples/dqn.py
@@ -195,7 +195,7 @@ def training_step(self, batch: Any) -> Tensor:
 if __name__ == "__main__":
     ml.seed_everything(42, gpu_dtm=False)
     batch_size = 32
-    max_epochs = 10
+    max_epochs = 20
     hparams = {
         "device_ids": device_ids,
         "memo_capacity": 1000,
diff --git a/examples/nlp.py b/examples/nlp.py
index 41d699d..a84aa2e 100644
--- a/examples/nlp.py
+++ b/examples/nlp.py
@@ -103,6 +103,7 @@ def tokenize_function(example):
         dataset["train"], dataset["validation"], dataset["test"], **hparams["dataloader_hparams"])
     #
     model = BertForSequenceClassification.from_pretrained(model_name)
+    ml.freeze_layers(model, ["bert.embeddings."] + [f"bert.encoder.layer.{i}." for i in range(2)], True)
     optimizer = getattr(optim, hparams["optim_name"])(model.parameters(), **hparams["optim_hparams"])
     metrics: Dict[str, Metric] = {
         "loss": MeanMetric(),
diff --git a/mini_lightning/mini_lightning.py b/mini_lightning/mini_lightning.py
index 007fa3c..be32d5e 100644
--- a/mini_lightning/mini_lightning.py
+++ b/mini_lightning/mini_lightning.py
@@ -51,7 +51,7 @@ def __init__(
     ) -> None:
         """
         get_core_metric: Get the core_metric for saving the model. 
-            The higher, the better. If lower is better, you can return a negative number.
+            The higher, the better. If lower is better, you can return a negative number. 
         hparams: Hyperparameters to be saved
         """
         self.model = model
@@ -478,7 +478,8 @@ def _epoch_end(self, mes: Dict[str, float], metric: Optional[float]) -> bool:
             is_best = True
         #
         self._remove_ckpt("last")
-        ckpt_fname = f"last-epoch={self.global_epoch}-metric={metric:.6f}.ckpt"
+        metric_str = "None" if metric is None else f"{metric:.6f}"
+        ckpt_fname = f"last-epoch={self.global_epoch}-metric={metric_str}.ckpt"
         self.last_ckpt_path = os.path.join(self.ckpt_dir, ckpt_fname)
         self.lmodel.save_checkpoint(self.last_ckpt_path)
         # 2. result saving
diff --git a/mini_lightning/utils.py b/mini_lightning/utils.py
index 14f32d3..be3dfb9 100644
--- a/mini_lightning/utils.py
+++ b/mini_lightning/utils.py
@@ -28,7 +28,7 @@
     "en_parallel", "de_parallel", "de_sync_batchnorm", "select_device",
     "_remove_keys", "smart_load_state_dict",
     "test_time", "seed_everything", "time_synchronize", "multi_runs",
-    "print_model_info", "save_to_yaml"
+    "print_model_info", "save_to_yaml", "freeze_layers"
 ]
 #
 
@@ -293,8 +293,8 @@ def print_model_info(model: Module, inputs: Optional[Tuple[Any, ...]] = None) ->
     s = [
         f"{model.__class__.__name__}: ",
         f"{n_layers} Layers, ",
-        f"{n_params:.4f}M Params, ",
-        f"{n_grads:.4f}M Grads, ",  # Trainable Params(no freeze)
+        # Grads: Trainable Params(no freeze). Params-Grads: freeze
+        f"{n_params:.4f}M Params ({n_grads:.4f}M Grads), ",
         f"{n_buffers:.4f}M Buffers",
     ]
     if inputs is not None:
@@ -311,3 +311,16 @@ def print_model_info(model: Module, inputs: Optional[Tuple[Any, ...]] = None) ->
 def save_to_yaml(obj: Any, file_path: str, encoding: str = "utf-8", mode: str = "w") -> None:
     with open(file_path, mode, encoding=encoding) as f:
         yaml.dump(obj, f)
+
+
+def freeze_layers(model: Module, layer_prefix_names: List[str], verbose: bool = True) -> None:
+    # e.g. ml.freeze_layers(model, ["bert.embeddings."] + [f"bert.encoder.layer.{i}." for i in range(2)], True)
+    for n, p in model.named_parameters():
+        requires_grad = True
+        for lpn in layer_prefix_names:
+            if n.startswith(lpn):
+                requires_grad = False
+                break
+        if verbose:
+            logger.info(f"Setting {n}.requires_grad: {requires_grad}")
+        p.requires_grad_(requires_grad)
diff --git a/setup.py b/setup.py
index 42a9747..01c97a9 100644
--- a/setup.py
+++ b/setup.py
@@ -21,7 +21,7 @@ def read_file(path: str) -> str:
 ]
 setup(
     name="mini-lightning",
-    version="0.1.1.dev0",
+    version="0.1.1",
     description=description,
     long_description=long_description,
     long_description_content_type='text/markdown',
diff --git a/tests/test_all.py b/tests/test_all.py
index e3c1520..d074d9a 100644
--- a/tests/test_all.py
+++ b/tests/test_all.py
@@ -1,9 +1,9 @@
 import unittest as ut
-import mini_lightning as ml
 #
 from test_lrs import *
 from test_utils import *
 from test_visualize import *
+from test_mini_lightning import *
 #
 if __name__ == "__main__":
     # run in mini-lightning folder: `python tests/test_all.py`
diff --git a/tests/test_mini_lightning.py b/tests/test_mini_lightning.py
new file mode 100644
index 0000000..8771db0
--- /dev/null
+++ b/tests/test_mini_lightning.py
@@ -0,0 +1,11 @@
+import os
+import unittest as ut
+
+
+class TestML(ut.TestCase):
+    def test_ml(self):
+        os.system("python examples/test_env.py")
+
+
+if __name__ == "__main__":
+    ut.main()