def _register_update_callbacks(self, update_callbacks):
        if update_callbacks is None:
            update_callbacks = []
        # If it's iterable, we're fine. If not, it's a single callback,
        # so wrap it in a list.
        try:
            iter(update_callbacks)
            self.update_callbacks = update_callbacks
        except TypeError:
            self.update_callbacks = [update_callbacks]
Fail if C{instance} is not an instance of the given class or of
dataset/ETHPy150Open lisa-lab/pylearn2/pylearn2/training_algorithms/training_algorithm.py/TrainingAlgorithm._register_update_callbacks--crossover with--dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/trial/unittest.py/_Assertions.failUnlessIsInstance