'Checks whether a specific hook is in its default state.
Args:
cls: A ndb.model.Model class.
default_hook: Callable specified by ndb internally (do not override).
hook: The hook defined by a model class using _post_*_hook.
Raises:
TypeError if either the default hook or the tested hook are not callable.'

@staticmethod
def _is_default_hook(default_hook, hook):

    if (not hasattr(default_hook, '__call__')):
        raise TypeError('Default    hooks    for    ndb.model.Model    must    be    callable')
    if (not hasattr(hook, '__call__')):
        raise TypeError('Hooks    must    be    callable')
    return (default_hook.im_func is hook.im_func)
