@Test public void isOffByDefault() { assertFalse(light.isOn()); }
public boolean isOn() { return isOn; }
Light { public boolean isOn() { return isOn; } }
Light { public boolean isOn() { return isOn; } Light(int number); }
Light { public boolean isOn() { return isOn; } Light(int number); boolean isOn(); int number(); void turnOff(); void turnOn(); }
Light { public boolean isOn() { return isOn; } Light(int number); boolean isOn(); int number(); void turnOff(); void turnOn();  }