def test_view_delattr(attr, subset_func):
    base = gen_adata((10, 10))
    orig_hash = joblib.hash(base)
    subset = base[subset_func(base.obs_names), subset_func(base.var_names)]
    empty = ad.AnnData(obs=subset.obs[[]], var=subset.var[[]])

    delattr(subset, attr)

    assert not subset.is_view
    # Should now have same value as default
    assert_equal(getattr(subset, attr), getattr(empty, attr))
    assert orig_hash == joblib.hash(base)  # Original should not be modified
def deadline_for_course(cls, course_key):
        """
        Retrieve the verification deadline for a particular course.

        Arguments:
            course_key (CourseKey): The identifier for the course.

        Returns:
            datetime or None

        """
        try:
            deadline = cls.objects.get(course_key=course_key)
            return deadline.deadline
        except cls.DoesNotExist:
            return None