diff --git a/iwf/registry.py b/iwf/registry.py
index b5e0da9..7317f20 100644
--- a/iwf/registry.py
+++ b/iwf/registry.py
@@ -86,11 +86,15 @@ def _register_internal_channels(self, wf: ObjectWorkflow):
         wf_type = get_workflow_type(wf)
 
         if self._internal_channel_type_store[wf_type] is None:
-            self._internal_channel_type_store[wf_type] = TypeStore(Type.INTERNAL_CHANNEL)
+            self._internal_channel_type_store[wf_type] = TypeStore(
+                Type.INTERNAL_CHANNEL
+            )
 
         for method in wf.get_communication_schema().communication_methods:
             if method.method_type == CommunicationMethodType.InternalChannel:
-                self._internal_channel_type_store[wf_type].add_internal_channel_def(method)
+                self._internal_channel_type_store[wf_type].add_internal_channel_def(
+                    method
+                )
 
     def _register_signal_channels(self, wf: ObjectWorkflow):
         wf_type = get_workflow_type(wf)
diff --git a/iwf/type_store.py b/iwf/type_store.py
index 639c8d2..f329303 100644
--- a/iwf/type_store.py
+++ b/iwf/type_store.py
@@ -11,6 +11,7 @@ class Type(Enum):
     # DATA_ATTRIBUTE = 2
     # SIGNAL_CHANNEL = 3
 
+
 class TypeStore:
     _class_type: Type
     _name_to_type_store: dict[str, Optional[type]]
@@ -40,7 +41,6 @@ def add_internal_channel_def(self, obj: CommunicationMethod):
             )
         self._do_add_to_store(obj.is_prefix, obj.name, obj.value_type)
 
-
     def _do_get_type(self, name: str) -> Optional[type]:
         if name in self._name_to_type_store:
             return self._name_to_type_store[name]
@@ -62,7 +62,7 @@ def _do_add_to_store(self, is_prefix: bool, name: str, t: Optional[type]):
 
         if name in store:
             raise WorkflowDefinitionError(
-                            f"{self._class_type} name/prefix {name} already exists")
+                f"{self._class_type} name/prefix {name} already exists"
+            )
 
         store[name] = t
-