# Determine if `self` is a prime number.
    # Return 2 if `self` is prime, return 1 if `self` is probably prime and
    # return 0 if `self` is definitely not a prime number.
    #
    # This function begins by trying some divisions with small number to find if
    # there is other factors then `self` and one. After that, it uses the
    # Miller-Rabin probabilistic primality tests. The probability of a non-prime
    # being identified as probably prime with that test is less than
    # `4^(-reps)`. It is recommended to use a `reps` value between 15 and 50.
    #
    #     assert((0x10001).to_bi.probab_prime(15) == 2)
    fun probab_prime(reps: Int): Int do
        return val.probab_prime_p(reps.to_i32)
    end