class Vault:
    def __init__(self):
        self._treasure = 'gold'
        self._original_attrs = self.__dict__.copy()

    @property
    def treasure(self):
        if self.__dict__ != self._original_attrs:
            print('Attribute deleted!')
        return self._treasure
    def stuff(self):
        ...

    def __setattr__(self, key, value):
        self.__dict__[key] = value
        if key != '_original_attrs' and hasattr(self, '_original_attrs') and self.__dict__ != self._original_attrs:
            print('Attribute deleted!')

    def __call__(self, *args):
        print(f"attempt to call {args}")

v = Vault()
v(1,2,3)