gossip.unregister_token does not work as expected

[ayalash]

The following code fails on AssertionError:

import gossip

@gossip.register('a.b', token='token')
def foo():
    pass

gossip.unregister_token('token')
assert not gossip.get_all_registrations()  # <= Raise AssertionError

[ayalash]

gossip.untergister_token calls gossip.get_global_group().unregister_token(token).
There are two bugs in the code of Gossip.unregister_token, that I found so far:

• It uses Group.iter_hooks which does not iterate the hooks of its subgroups.
• It invalidate all registrations of each of its hooks by using Hook.get_registrations. The method does not returns the empty registration of the hook.

[ayalash]

@vmalloc I just saw this method (during my debugging of this issue):

In [10]: gossip.registration.Registration.can_be_called??
Signature: gossip.registration.Registration.can_be_called(self)
Source:
    def can_be_called(self):
        return True
File:      ~/src/github/gossip/gossip/registration.py
Type:      function

Do you remember what is the purpose of this method?
I didn't find any code that uses it (not even unittests).

Should we change the return value of this method (to False) for empty registrations?

[vmalloc]

@ayalash I think it's a remainder of an old code for computing dependencies

[vmalloc]

Doesn't seem to be needed anymore though