'Invalidates the association with the given handle.
@type assoc_handle: str
@param dumb: Is this association used with dumb mode?
@type dumb: bool'

def invalidate(self, assoc_handle, dumb):

    if dumb:
        key = self._dumb_key
    else:
        key = self._normal_key
    self.store.removeAssociation(key, assoc_handle)
