### Question:
RxShamir { @Nonnull public static RxShamir create(@Nonnull final SecureRandom random) { return new RxShamir(random); } RxShamir(@Nonnull final SecureRandom random); @Nonnull static RxShamir create(@Nonnull final SecureRandom random); @Nonnull Observable<Share> createShares(
      @Nonnull final BigInteger secret,
      @Nonnull final CreationScheme creationScheme); @Nonnull Single<BigInteger> recoverSecret(
      @Nonnull final Set<Share> shares,
      @Nonnull final RecoveryScheme recoveryScheme);  }### Answer:
@Test(expected = IllegalArgumentException.class) public void testInstantiateStatically_nullRandom() { RxShamir.create(null); }
@Test public void testInstantiateStatically_nonNullRandom() { RxShamir.create(new SecureRandom()); }