### Question:
BigIntegerValueDto { public boolean isZero() { return BigInteger.ZERO.equals(this.value); }  boolean isPositive(); boolean isNegative(); boolean isZero(); boolean isNonZeroPositive(); boolean isNonZeroNegative(); @Override String toString();  }### Answer:
@Test public void shouldSucceedIsZero() { BigInteger value = new BigInteger("0"); BigIntegerValueDto dto = new BigIntegerValueDto(value); assertTrue("Value should be zero.", dto.isZero()); }
@Test public void shouldSucceedIsZero_negative0() { BigInteger value = new BigInteger("-0"); BigIntegerValueDto dto = new BigIntegerValueDto(value); assertTrue("Value should be zero.", dto.isZero()); }