def unregister(self, cls):
try:
if self.__values[cls.key] != cls:
# dont allow unregistering of arbitrary provider
raise NotRegistered(cls.key)
except KeyError:
# we gracefully handle a missing provider
return
del self.__values[cls.key]
def get(self, key, **kwargs):
try:
cls = self.__values[key]
except KeyError:
raise NotRegistered(key)
return cls(**kwargs)