def test_modify_view_component(matrix_type, mapping_name):
    adata = ad.AnnData(
        np.zeros((10, 10)),
        **{mapping_name: dict(m=matrix_type(asarray(sparse.random(10, 10))))},
    )
    init_hash = joblib.hash(adata)

    subset = adata[:5, :][:, :5]
    assert subset.is_view
    m = getattr(subset, mapping_name)["m"]
    m[0, 0] = 100
    assert not subset.is_view
    assert getattr(subset, mapping_name)["m"][0, 0] == 100

    assert init_hash == joblib.hash(adata)
def deadlines_for_courses(cls, course_keys):
        """
        Retrieve verification deadlines for particular courses.

        Arguments:
            course_keys (list): List of `CourseKey`s.

        Returns:
            dict: Map of course keys to datetimes (verification deadlines)

        """
        all_deadlines = cache.get(cls.ALL_DEADLINES_CACHE_KEY)
        if all_deadlines is None:
            all_deadlines = {
                deadline.course_key: deadline.deadline
                for deadline in VerificationDeadline.objects.all()
            }
            cache.set(cls.ALL_DEADLINES_CACHE_KEY, all_deadlines)

        return {
            course_key: all_deadlines[course_key]
            for course_key in course_keys
            if course_key in all_deadlines
        }