Added more test files from lectures.

test22.py

@@ -0,0 +1,17 @@
+class Vault2:
+    def __init__(self):
+        self._treasure = "gold"
+        self._original_dict = dict(self.__dict__)
+
+    def __setattr__(self, name, value):
+        if name != "_treasure" and name in self.__dict__ and self._original_dict.get(name) != value:
+            print("attribute deleted!")
+        self.__dict__[name] = value
+
+    @property
+    def treasure(self):
+        if self.__dict__ != self._original_dict:
+            print("attribute deleted!")
+        return self._treasure
+v = Vault2()
+print(v.treasure)