diff --git a/examples/workflow_by_code/environment.yml b/examples/workflow_by_code/environment.yml
new file mode 100644
index 0000000..2923bdb
--- /dev/null
+++ b/examples/workflow_by_code/environment.yml
@@ -0,0 +1,27 @@
+name: learnware_example_env
+channels:
+  - defaults
+dependencies:
+  - _libgcc_mutex=0.1=main
+  - _openmp_mutex=5.1=1_gnu
+  - ca-certificates=2023.01.10=h06a4308_0
+  - ld_impl_linux-64=2.38=h1181459_1
+  - libffi=3.4.2=h6a678d5_6
+  - libgcc-ng=11.2.0=h1234567_1
+  - libgomp=11.2.0=h1234567_1
+  - libstdcxx-ng=11.2.0=h1234567_1
+  - ncurses=6.4=h6a678d5_0
+  - openssl=1.1.1t=h7f8727e_0
+  - pip=23.0.1=py38h06a4308_0
+  - python=3.8.16=h7a1cb2a_3
+  - readline=8.2=h5eee18b_0
+  - setuptools=66.0.0=py38h06a4308_0
+  - sqlite=3.41.2=h5eee18b_0
+  - tk=8.6.12=h1ccaba5_0
+  - wheel=0.38.4=py38h06a4308_0
+  - xz=5.2.10=h5eee18b_1
+  - zlib=1.2.13=h5eee18b_0
+  - pip:
+    - joblib==1.2.0
+    - learnware==0.0.1.99
+    - numpy==1.19.5
diff --git a/learnware/learnware/base.py b/learnware/learnware/base.py
index 8a2d197..e2142d2 100644
--- a/learnware/learnware/base.py
+++ b/learnware/learnware/base.py
@@ -45,7 +45,7 @@ class Learnware:
             logger.info("The learnware had been instantiated, thus the instantiation operation is ignored!")
         elif isinstance(self.model, dict):
             model_module = get_module_by_module_path(self.model["module_path"])
-            return getattr(model_module, self.model["class_name"])(**self.model.get("kwargs", {}))
+            self.model = getattr(model_module, self.model["class_name"])(**self.model.get("kwargs", {}))
         else:
             raise TypeError(f"Model must be BaseModel or dict, not {type(self.model)}")
 
diff --git a/learnware/market/base.py b/learnware/market/base.py
index 9be0d9c..069209c 100644
--- a/learnware/market/base.py
+++ b/learnware/market/base.py
@@ -49,6 +49,9 @@ class BaseMarket:
         learnmarket = BaseMarket()
     """
 
+    def __init__(self, market_id: str = None):
+        self.market_id = market_id
+
     def reload_market(self, market_path: str, semantic_spec_list_path: str) -> bool:
         """Reload the market when server restared.
 
diff --git a/learnware/market/easy.py b/learnware/market/easy.py
index 9e25db6..130d918 100644
--- a/learnware/market/easy.py
+++ b/learnware/market/easy.py
@@ -23,7 +23,7 @@ class EasyMarket(BaseMarket):
     NOPREDICTION_LEARNWARE = 0
     PREDICTION_LEARWARE = 1
 
-    def __init__(self, rebuild: bool = False):
+    def __init__(self, market_id: str = None, rebuild: bool = False):
         """Initialize Learnware Market.
         Automatically reload from db if available.
         Build an empty db otherwise.