def test_view_mixin_copies_data(adata, array_type: type, attr):
    N = 100
    adata = ad.AnnData(
        obs=pd.DataFrame(index=np.arange(N)), var=pd.DataFrame(index=np.arange(N))
    )

    X = array_type(sparse.eye(N, N).multiply(np.arange(1, N + 1)))
    if attr == "X":
        adata.X = X
    else:
        getattr(adata, attr)["arr"] = X

    view = adata[:50]

    if attr == "X":
        arr_view = view.X
    else:
        arr_view = getattr(view, attr)["arr"]

    arr_view_copy = arr_view.copy()

    if sparse.issparse(X):
        assert not np.shares_memory(arr_view.indices, arr_view_copy.indices)
        assert not np.shares_memory(arr_view.indptr, arr_view_copy.indptr)
        assert not np.shares_memory(arr_view.data, arr_view_copy.data)

        arr_view_copy.data[0] = -5
        assert not np.array_equal(arr_view_copy.data, arr_view.data)
    else:
        assert not np.shares_memory(arr_view, arr_view_copy)

        arr_view_copy[0, 0] = -5
        assert not np.array_equal(arr_view_copy, arr_view)
def set_deadline(cls, course_key, deadline, is_explicit=False):
        """
        Configure the verification deadline for a course.

        If `deadline` is `None`, then the course will have no verification
        deadline.  In this case, users will be able to verify for the course
        at any time.

        Arguments:
            course_key (CourseKey): Identifier for the course.
            deadline (datetime or None): The verification deadline.

        """
        if deadline is None:
            VerificationDeadline.objects.filter(course_key=course_key).delete()
        else:
            record, created = VerificationDeadline.objects.get_or_create(
                course_key=course_key,
                defaults={"deadline": deadline, "deadline_is_explicit": is_explicit}
            )

            if not created:
                record.deadline = deadline
                record.deadline_is_explicit = is_explicit
                record.save()