public static Autoscaling empty() {
        return empty("");
    }
@Test
    public void autoscaling_respects_group_size_limit() {
        var min = new ClusterResources( 2, 2, new NodeResources(1, 1, 10, 1));
        var now = new ClusterResources(5, 5, new NodeResources(3.0, 10, 100, 1));
        var max = new ClusterResources(18, 6, new NodeResources(100, 1000, 10000, 1));
        var fixture = DynamicProvisioningTester.fixture()
                                               .awsProdSetup(true)
                                               .initialResources(Optional.of(now))
                                               .capacity(Capacity.from(min, max, IntRange.of(2, 3), false, true, Optional.empty(), ClusterInfo.empty()))
                                               .build();
        fixture.tester().clock().advance(Duration.ofDays(2));
        fixture.loader().applyCpuLoad(0.6, 240);
        fixture.tester().assertResources("Scaling cpu up",
                                         12, 6, 3.2,  4.2, 27.5,
                                         fixture.autoscale());
    }