@Test
public void testHashcode() {

    Liquid liquid1 = new Liquid(1, SimulationConstants.MIN_TEMPERATURE, new Color(1, 1, 1));
    Liquid liquid2 = new Liquid(1, SimulationConstants.MIN_TEMPERATURE, new Color(1, 1, 1));
    assertEquals(liquid1.hashCode(), liquid2.hashCode());
    liquid2 = new Liquid(2, SimulationConstants.MIN_TEMPERATURE, new Color(1, 1, 1));
    assertNotEquals(liquid1.hashCode(), liquid2.hashCode());
    liquid2 = new Liquid(1, SimulationConstants.MAX_TEMPERATURE, new Color(1, 1, 1));
    assertNotEquals(liquid1.hashCode(), liquid2.hashCode());
}