not easy/possible to write 'make resource dirty' decorator

[Robert Collins]

I want to be able to write code roughly like:

class _Decorated(object):
    """A decorated resource."""

    def __add__(self, other):
        return self.decorated.__add__(other)

    def __getattr__(self, name):
        return getattr(self.decorated, name)

class AlwaysDirtyResourceDecorator(TestResource):
    """A resource decorator that makes another resource dirty."""

    def __init__(self, decorated):
        TestResource.__init__(self)
        self.resources = [('decorated', decorated)]
        self._dirty = True

    def make(self, dependency_resources):
        self.resource = _Decorated()
        self.resources[0][1].dirtied(dependency_resources['decorated'])
        return self.resource

    def clean(self, resource):
        self.resource = None

    def isDirty(self):
        self.resources[0][1].dirtied(self.resource.decorated)
        return True

but it doesn't work today; permitting decoration like this would be very useful.