public double cost() {
        return nodes * nodeResources.cost();
    }
@Test
    void testCost() {
        ClusterResources r1 = new ClusterResources(3, 1, new NodeResources(2,  8, 50, 1));
        ClusterResources r2 = new ClusterResources(3, 1, new NodeResources(2, 16, 50, 1));
        assertEquals(2.232, r1.cost() + r2.cost(), 0.01);
    }