@Test
public void testMaximumlValue() {

    assertEquals(Double.MAX_VALUE, l1.maximumValue(network, LOAD), 0.);
    assertEquals(-20, l3.maximumValue(network), 0.);
    assertEquals(-20, l3.maximumValue(network, GENERATOR), 0.);
    assertEquals(100, l3.maximumValue(network, LOAD), 0.);
}