Closes faif#377: No return value expeced 🐛

Author: g-paras

patterns/creational/prototype.py

@@ -29,7 +29,7 @@ def __init__(self, value: str = "default", **attrs: Any) -> None:
         self.value = value
         self.__dict__.update(attrs)
 
-    def clone(self, **attrs: Any) -> None:
+    def clone(self, **attrs: Any) -> "Prototype":
         """Clone a prototype and update inner attributes dictionary"""
         # Python in Practice, Mark Summerfield
         # copy.deepcopy can be used instead of next line.