@Override
  public boolean test(Creature t) {
    return t.getColor().equals(color);
  }
@Test
  void testColor() {
    final var greenCreature = mock(Creature.class);
    when(greenCreature.getColor()).thenReturn(Color.GREEN);

    final var redCreature = mock(Creature.class);
    when(redCreature.getColor()).thenReturn(Color.RED);

    final var greenSelector = new ColorSelector(Color.GREEN);
    assertTrue(greenSelector.test(greenCreature));
    assertFalse(greenSelector.test(redCreature));

  }