/** Test of fillMilkTank method, of class AdvancedCoffeeMachine. */ @Test public void testFillMilkTank() { System.out.println("fillMilkTank"); int amount = 50; AdvancedCoffeeMachine instance = new AdvancedCoffeeMachine(); String expResult = "\"message\":\"Finished filling up " + amount + "ml of milk\""; String result = instance.fillMilkTank(amount); assertEquals(expResult, result); }