def untrust(self, scope, vk):
        """Stop trusting a particular key for given scope."""
        self.data['verifiers'].remove({'scope': scope, 'vk': vk})
        return self
def untrust ( self , scope , vk ) : self . data [ 'verifiers' ] . remove ( { 'scope' : scope , 'vk' : vk } ) return self
Stop trusting a particular key for given scope.