public void TestDetach_WithSelectedCore_WithTwoFragments_ShouldDetachTopFragment()
{
ICore dummyCore = new SystemCore("A", 100);
IFragment dummyFragment = new NuclearFragment("Test", 1);
IFragment anotherDummyFragment = new NuclearFragment("Test2", 1);
dummyCore.AttachFragment(dummyFragment);
dummyCore.AttachFragment(anotherDummyFragment);
this.testNuclearPowerPlant.AttachCore(dummyCore);
this.testNuclearPowerPlant.SelectCore("A");
ICommand testCommand = new DetachFragmentCommand(this.testNuclearPowerPlant);
String actualMessage = testCommand.Execute();
String expectedMessage = "Successfully detached Fragment Test2 from Core A!";
Assert.AreEqual(expectedMessage, actualMessage, "DetachFragment command does not work correctly!");
}