def test_get_root_on_create(self):
        root_on_create_val = Instance.get_root_on_create(
            'redis')
        self.assertFalse(root_on_create_val)
def merge(left, right):
    if left is None:
        return right
    if right is None:
        return left
    if left.prio > right.prio:
        left.right = merge(left.right, right)
        left.update()
        return left
    else:
        right.left = merge(left, right.left)
        right.update()
        return right