@Test
public void testEquals() {

    FourDigitNumber num1 = new FourDigitNumber(mockSlot, 0, 0, 0, 0);
    FourDigitNumber num2 = new FourDigitNumber(mockSlot, 0, 0, 0, 0);
    assertEquals(num1, num2);
    assertEquals(num1.getNumber(), num2.getNumber());
    assertEquals(num1.getFirstDigit(), num2.getFirstDigit());
    assertEquals(num1.getSecondDigit(), num2.getSecondDigit());
    assertEquals(num1.getThirdDigit(), num2.getThirdDigit());
    assertEquals(num1.getFourthDigit(), num2.getFourthDigit());
    assertArrayEquals(num1.getDigits(), num2.getDigits());
    assertEquals(num1.stringValue(), num2.stringValue());
    assertEquals(num1.getSlot(), num2.getSlot());
    assertEquals(num1.hashCode(), num2.hashCode());
    assertEquals(num1.toString(), num2.toString());
}