BigIntegerModulus implements Serializable { @Override public String toString() { return "BigIntegerModulus{" + "value=" + value + '}'; } BigIntegerModulus(BigInteger value); @Override String toString();  }
@Test public void testOfToString() { BigInteger modulus = new BigInteger("13"); Assert.assertThat( new BigIntegerModulus(modulus).toString(), Matchers.containsString(modulus.toString())); Assert.assertThat( new BigIntegerModulus(modulus).toString(), Matchers.containsString("BigIntegerModulus")); }