An instance of this class is used to generate a stream of pseudorandom numbers. The class uses a
64-bit seed, which is modified using a linear congruential formula. see
Random64 is a pseudorandom algorithm(LCG). Therefore, we will get same sequence if seeds are
the same. This main will test how many calls nextLong() it will get the same seed. We do not
need to save all numbers (that is too large). We could save once every 100000 calls nextLong().
If it get a same seed, we can detect this by calling nextLong() 100000 times continuously.